Artillers Luger at Gunshow - missing sight - questions

[Revolvr]

Hi fellow Luger fans,

Saw an artillery Luger at a gun show today and thought about buying it. But I had a couple of concerns.

This is a 1917 dated DWM model, all part numbers visible matched except the rear toggle link. It was missing the sight that belongs on the barrel. I think this sight had been lost and a previous owner decided then to replace the rear toggle with a regular toggle with the V-notch for a sight.

The dealer said this wasn't a real artillery piece and that it had been created from parts. But since all obvious parts match except the rear toggle, I think this is an actual artillery piece with a missing sight and the wrong rear toggle.

Otherwise it was in good shape, bluing looked original and at 50-70%, grips looked good. Didn't see the magazine.

So my questions are:

Would it be reasonable for me to expect to find a correct barrel site somewhere I could re-attach? Is it reasonable to run across the correct rear toggle piece? Obviously it would not have the right numbers, but at least it would be the right part.

And what would be a rough value of the piece in it's current configuration? Would the value go up if I find the sight and proper toggle part?

Thanks much,

-- Dan