I’m the original owner and it has had only occasional use. There are two modifications: one an adjustment-improving detail added by a machinist -- the brass bar and thumbscrews shown in lower right, and a wooden setup (in both photos) that I made for cutting 45-degree splines for 90-degree box corners.
This highly desirable piece is priced at $250. Good ones are selling for over $300 plus shipping on EBAY. This one must be see to truly appreciate how nice it is.