I know the feeling. They made several changes over the years and the old ones are terrible to get info on. Usually they are in otherwise very good shape, so there are still lots of them out there. We get them coming in at the shop where I work, but unless it is fairly new, they aren't worth the time we would have to charge for the fixing.
If you can do the work yourself though, you might stand a chance. V-springs can be made out of flat stock from Brownells, and they even sell a spring making guide. DGW has a low priced guide as well as 1018 spring stock.
I wish someone would produce a book about smithing the H&R's, but I haven't heard of it if they have. I would really like to know what kind of shape the hand spring is. Seems a shame to let a gun sit idle for lack of a few odd parts.