You know, I used to play when games didn't have much in the way of artwork, were badly typeset, and were full of misspellings with different size fonts and overlap in the margins. The books also were not 400 pages, didn't cost $60, and were in most cases better then what is being turned out now.
If the ideas are still in the head, they could be done on the computer pretty quick, even if they were only available on PDF. They don't need artwork to sell. Since there wouldn't be any publishing overhead, it seems that even if a few people bought there would still be a profitable market.