I've been looking for a supplier of a rack for a T140 for months and so far have failed to find any companies that produce luggage racks for classic bikes - so I think you're going to struggle to get a new one. I ended up polishing up a really rusty old one I got hold of.
There might be someone making them in the USA or maybe down under, however I have not found anyone yet.
Good luck with the auto jumbles.....