To the best of my knowledge, Polyprint was a VC paper - though I personally never used it.
A Google search turned up this reference which contains a smidging of information that might be useful:
There was also uncertainty about whether the paper should have the developing agent incorporated into it. In the 1980s, many RC papers did; the purpose was to facilitate machine processing, and to eliminate one cause of "poor blacks," namely incomplete developing.
But then it was shown that a print need not have maximum development in order to have good blacks. Kodak introduced a paper, Polyprint (later Polymax), that allowed the user to vary the development to control overall density. I adopted it enthusiastically.
Meanwhile, Ilford was pioneering ways to make fixing and washing go faster. Kodak's paper has a relatively hard emulsion that requires 1 minute to fix and 4 minutes to wash. No information about development though...
This was from
http://www.covingtoninnovations.com/michael/blog/0506/index.htmlThere was someone on APUG a while ago trying to use it. The post is at
http://www.apug.org/forums/306181-post1.htmlAnd another poster claims to have used it at
http://www.apug.org/forums/380752-post16.htmlMaybe it's worth an email to the OPs above to see what they did.
If you hadn't already found the above yourself, then I hope they help a little.