I have owned both the R-115 and R-117 and both are very sweet sounding receivers. IMO, both have exactly the same sound signature with great dynamic headroom with the R-117 boasting a true, if not conservative 160w/ch. Mine were in almost mint condition and neither needed any servicing at all.
With that said, I would at least get an estimate for repairs/refurbishing because I think it would be worth it if not more than around $150.00. Now if you had the R-117, I would up that to about $250.00.