Rod Stewart will keep him in business for a long long time...
I've always felt there would be a strong market for laser cut trusses in a variety of styles. Especially for things like train sheds.
I fabricated a bunch out of scrap rail, enough to make a 3' long train shed x 8 tracks (1/platform/2/platform/2/p/2/p/1) and they sold on ebay for like $60! If I recall, there were a ton of watchers and bidders, too.
Freight houses would be another good project:

Lee