I haven't seen veggie corned beef offered anyplace. But a local vegetarian-friendly restaurant used to serve a Tempeh Reuben which was quite good- just the thing on a cold day when I wanted something hot, greasy, and a bit decadent. They were pretty accomodating to vegans. This sandwich could be made with your choice of real cheese, soy cheese, or without it altogether. I don't remember that the tempeh tasted that much like corned beef, but I think the sandwich was made on rye bread with sauerkraut and russian dressing, one of the cheeses, and then grilled. I can't remember if it had sauteed onions on it or not.
Peasant (1963-1972) and Fluffy (1970s?-1982- I think of you as 'Ambrose' now)- Your spirits outshone some humans I have known. Be happy forever.