Recently we stumbled across a HK Silver (Pirate) THPS version in a thrift store for $1, as it turned out the disc contained not the retail version of the game but a previously unknown build dated 07-07-1999 this pre-dates the ‘later’ beta by 3 days.
Unfortunately the disc was too damaged to get a good read from it but we did have managed to grab the PSX.EXE, CD.HED and CD.WAD. These are the main data files for the game, what remains are STR files that differ from any other beta we have available.
Research continues into this build which you can see on the SK707 page. This also sparked my interest to update my long standing THPS page with some additional scene files I found lying around on various hard drives and sites.