I ask because I sent my great grandfather's Gruen Verithin to be serviced 3 or 4 months ago and I'm still awaiting its return. They contacted me yesterday and told me that the only part that they are still waiting on is the mainspring. Now, I'm not really sure what mainspring it uses, but should it really take this long to locate one?
Thanks for your insight.
Here's a photo I took of the movement (17j, 5 positions, blah, blah) before I sent it out. Hopefully someone can identify it?