Thanks for the link Longknife 76. They have a better selection of parts than Dixie.
I believe your Walker may be the same make as the one I picked up about four years ago. Like you, I can find no makers mark.
I read somewhere a while back, that all Italian revolvers have a makers mark on them, but, some of the early ones were marked where disassembly is required to see them. I haven't needed to take mine down since reading that, but if you take yours apart to clean and tune it, look it over for letters or symbols, and if you find some, let me know, and maybe we can figure out who made them.
So far, I have determined mine may be an early ASM, by comparing the way the round part of the grip fits into the frame, to pictures of Walkers I have found surfing the net. Not sure though.
I know what you mean about the strong hammer (Main) spring, but I believe it needs to be that strong. 60 grains of black causes a lot of gasses to try exiting the nipples, and I think the strong spring helps keep it contained, and out of your face.
A friend of mine has a newer Uberti Dragoon, and I watched his kick the hammer back to half cock, when he shot a full (about 50 grains volume) dose of Triple 7. I decided to leave my main spring the way it is, after seeing that.
You are going to love shooting that old girl. Especially in low light. LOTS of fire out front !