There is an Excel card manifest that conveys all the information.
If a Vassal module is ever released, you might extract the card images from it.
I'd guess your chances of acquiring actual print files, or even quality/official PnP files, are next to zero. Your best hope would be some bootleg scans, the kosherness of which is squinty.
However ... As an alternative to low-quality home-made copies, may I suggest saving up your florins and actually buying the expansion? Yes I know it's going for premium price nowadays, but if you really want it, it will be worth the effort of acquiring the genuine article. Pony up and get the real thing! You can do it!
I mean you can make your own copy or you can buy a secondhand copy for a massively-inflated price, Sierra Madre Games gets the same amount of money either way. Don't know if I can stomach paying $90 for 60 cards. Really wish they would just reprint the damn thing.