Just looking through the entire site is like this. I would be worried about trying to zoom if you don't have larger versions of these images. To osgood's point, the purpose appears to make the cards readable, but zooming on a digital image does not make the image readable, it just makes the image more pixelated and thus unreadable.
Also all of these pages are HTML. This would end up being a ton of work. You are looking at hundreds, if not more than 1,000 pages of code. Have you considered migrating to a CMS and investing in a gallery plugin that fits your needs? Personally, with this extensive of a catalog, I would recommend going in that direction.