I'm using Group 5 Motorsports on Rte 8, just north of the city. The owner, Joe Serbin, loves working on all types of vehicles and has been very honest and helpful. (I believe my 110 was the first Defender he's worked on 😃, but I think another owner has since worked with him). Clean shop, all vehicles stored inside.
I tried calling dealers in the area, and they said they couldn't help me. There is also a garage out in Greensburg that was mentioned in the Pittsburgh Landrover Club website, but that's an hour outside of Pittsburgh.