The black vinyl, white label test pressings came in white inner sleeves. Ten copies were pressed, all handnumbered on the label on one side. Eight copies, numbers 2-5 and 7-10, have been on eBay since the first appeared in 2002, all sold by the same seller. The seller claimed to sell them for the Insipid Vinyl owner. Numbers 1 and 6 have not been seen yet.
It may seem odd that the test pressings for a picture disc release are pressed on regular black vinyl, but this is normal, as described in this document. Doing it as a regular vinyl pressing tests the audio quality of stampers just as well.  The metal plates were processed by Lee Plating as seen from the L-codes in the matrix codes, but both cutting studio and pressing plant are unknown.
The test pressings came with a signed certificate of authenticity (COA) with a brief manufacturing history, supposedly signed by the Insipid Vinyl owner. At first the COAs came on papers with a company letterhead and dated 2002.07.27, while later COAs dated 2003.10.15 and 2005.01.05 did not have company letterheads. The letter, transcribed below, contains a few things which are implausible and not entirely true:
I am the sole owner of the Insipid Vinyl label. The Nirvana/ Jesus Lizard split picture disc was manufactured in Los Angeles as there was no pressing plant in Australia that catered for picture discs.
Once the master DAT was received by the pressing plant (this was a completely different cut to the Touch & Go version), they manufactured 10 (ten) test pressings, which were done as normal singles, the pressing piant did not have the film to do the print part yet, the first set of film was not set at the appropriate DPI, and had to be redone (hence them done as black vinyl singles, time was tight). I asked the proprietor to number them and gave them the addresses where to send copies to band/ management for approval prior to manufacture (whoever had requested a test pressing got one) and once the appropriate people gave the test pressing the OK, corrected film was supplied in the interim to print the paper parts and the picture discs were manufactured.
All picture discs were then stickered with the band names (half were red stickers with white print, the other half black stickers with white print) and airfreighted back to Australia, where they were then sold and distributed.
Some of the information in the COA may be true, and some is less plausible. Whether or not there were pressing plants in Australia which pressed picture discs at the time is uncertain. According to an industry person in Australia, an unnamed plant had pressed them since the 80's, and CBS Records since 1990 or 1991 . Picture discs pressed by Modern Records in 1991 [3a] and Festival Records in 1990 [3b] have been found, but very few so it may have been unusual. Modern went out of business in 1991 [3c], and while Festival was active in 1993, I cannot find any records pressed by them in 1993 at all, only CDs [3d]. CBS operated under the name Sony Music Australia from 1991.01.11 [3e], and it is uncertain whether or not they kept pressing picture discs. It may be true that it was difficult to get some picture discs pressed domestically at the exact time this release was manufactured. There are a number of reasons why an Australian record label would have records pressed in the USA, so there is no need to make this information up.
The records were plated by Lee Plating in Los Angeles, so it makes sense that the records were pressed in Lost Angeles, too.
There is no reason to make proper picture disc test pressings. Even if the proper film and printed papers had been ready, it is highly unlikely that the plant would have done the test pressings on anything other than solid black vinyl.  If Insipid Vinyl for whatever reason insisted on having the test pressings as picture discs, any picture could have been used; the wrong DPI print of the final picture, or a blank picture. It is entirely possible that the Inspid Vinyl owner remembers this slightly wrong. They may very well have had the issue with bad film prior to pressing the retail pressing, but there is no reason that this should change any plans regarding the test pressings.
The COA also mentions that an unspecified amount of test pressings were sent to the bands and management for approval. In the first two auctions the seller claimed that eight test pressings went to Nirvana, their management, and The Jesus Lizard, and only the two copies the seller had listed up until then were kept by Insipid Vinyl. Over the following years the seller sold, or at least attempted to sell, all the eight copies shown below with changing stories of how many were sent to Nirvana or how he suddenly unearthed another. When listing copy 2, so far the last one, he still insisted that copy 1 was given to Kurt Cobain. Currently, only two copies are unaccounted for, but the letter implies that more than two were sent out. This part of the letter seems to be entirely untruthful.
Whether the seller is the Insipid Vinyl owner himself, operating on his behalf, or unaffiliated with him, it seems to be fabrications to hype the value of the records. The numbering may even have been added in conjunction with first listing the test pressings on eBay to further hype the value, and not back in 1993. The COA has been proven to not be entirely accurate and cannot be taken as a reliable source of information. There is also no proof who signed it. All this is quite unnecessary, because the records are all authentic, valuable Nirvana test pressings which would have sold for good money regardless of how many were or were not sent to Nirvana.
1. Copy 2
2. Copy 3
3. Copy 4
4. Copy 5
5. Copy 7, side A
6. Copy 7, side B
7. Copy 8
8. Copy 9
9. Copy 10