It's a shame

[Wilmurt]

Working with relatives in a different part of my family to acquire (I mean buy) an AAHE 12ga. (1910) that's been blued...everywhere (skeleton butt plate, barrels, trigger guard, frame, you name it) except for the forend latch, trigger and grip plate which have all been gold plated. The stock has been varnished and checkering is in quite good condition. The gun has been in "our family" since 1916 and no one knows when the gun was blued, or whether it was hot blue or cold blue and all people that would have knowledge are now deceased. My questions are, can a blued gun be restored to factory finish? How can you tell if it's been hot blued or cold blued? If hot blued, has that process effected the metallurgical properties where the metal could not be restored to factory finish? I'd like to save this gun if it is salvageable and know it will be expensive to do so but it may be worthwhile. PGCA letter says the gun was returned for restocking in 1916 abut no other work shows up. Your thoughts please. Thanks.