Hi Jim
As Adam says, minters go for £250 and sometimes more.

Polishing off the bluing from the barrel has de-valued the pistol as a collectors pistol
A re-blue (properly done by hot bluing) would be costly because of the pistols construction, unless you did some of the strip/preparation yourself

A FWB 65 in our club just changed hands for £175 and it was in excellent condition. It had been up for sale for quite a while despite a number of pistol collectors being members

So I would guess that if it is in excellent condition other than the shiny barrel, then £150 max would be very near the mark. If it has the box, manual and original tools then this adds to its value

John