You didn't even mention the first model long slide Lyman 48 receiver sight (that is, you mentioned a Lyman 48, but you didn't say which kind). That's a pretty valuable item in itself.
The rig reminds me of an early Griffin & Howe Springfield. However, I don't believe G&H installed the side mount. All the G&H installations I have seen used double thick screw heads and then milled the slots off after the mount was in place.
You didn't mention what you paid for the rifle, but I have a feeling you got a real bargain.
