I've not purchased any like you describe but sure seen a lot come through, friends bringing a gun over for something, grips or a check up or whatever.
It's like the lube or oil or whatever they put on was there so long it turned into adhesive. Makes ya wonder if they never cleaned it from new or oiled it up well and just left it for a very long time.
I know WD40 will do that for sure, I'm sure there are others that do the same.
Sometimes cleaning just means getting rid of the old lube and putting some fresh stuff on.
I know manufacturers really oil things up and put them in the plastic bags cause they never know how long they will sit on a distributors shelves.
My hats off to ya for saving a few lost unloved guns.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."