John Deere 690C Parts

Howdy - I'm wondering if anyone out there knows where I can obtain parts for a John Deere 690C Excavator. We purchased a 1984 & unfortunately have never been able to use it because the gear box was destroyed in it. We were dealing with a company named Funk who claimed to be able to obtain the parts & to our dismay they have told us that they have all the gears, but have not been able to obtain the housing for the gearbox. It has been months that they have been promising. So I was wondering if anyone knew of anyone who sold parts for this excavator or even if they had one hanging around that they would be willing to piece out parts for. Thanks, Allison