This is a little old now, but did you have any luck with this? These board are very rare, particularly models using Intel's cache module. This was designed specifically to work with the DX/50 for stability and performance purposes but not all manufacturers went for it because of the high cost.

brassicGamer wrote on 2022-11-21, 16:42:

This is a little old now, but did you have any luck with this? These board are very rare, particularly models using Intel's cache module. This was designed specifically to work with the DX/50 for stability and performance purposes but not all manufacturers went for it because of the high cost.

There are two listings on eBay now for the same CPU card and one says HP and the other DEC, but part numbers are the same. I have three Compaq Proliant CPU cards that also has a 486DX-50 with a cache chip. Bought another Compaq card but it came without cache so i got one similar on the eBay listings to use it as a donor. The price was quite different some years ago.