That may sound steep, but... I think it's a mistake to link the current market value with the cost of service. If it's worth using, IMO it's worth fixing.
I have a non-MLU 6x7 that I bought used in 1976 and had it serviced at Camera Techs, a local Seattle shop, in 2001. My notes:
4/26/01 Took it to Camera Techs. The foam around the focusing screen was visibly deteriorated allowing the prism to move/rattle up & down. Check also found meter underexposing by 2/3 stop, and shutter speeds off (1000 = 2000, 500 = 1000 or so, and 250 = about 400), recommend rebuild body and calibrate meter. They did so, going over everything, calibrating meter & shutter speeds, cleaned completely, replaced foam & seals. $303.55. I believe it had never had these kinds of service before.
There's been some inflation in the past 20 years since then, so maybe $400 isn't out of line now, though a simple CLA would be less invasive. I'd think there might be a shop in LA that can service it for you.