New to forum - my 1938 P08

[meadowlark]

I am now the proud owner of a P08 that belonged to my wife's uncle who served during WW2 in Germany and brought this back with him at war's end.
As you will see from the pictures shown here all parts (with the exception of the magazine) are unique to this weapon.
Since I am new to this forum I would like to know the possible value (although I doubt I'll be selling anytime soon) and also why it is so difficult to pull the toggle all the way back to the full open position.