Kenwood KR-10000 III questions

An acquaintance is liquidating his father’s estate and asked me to look through his record collection.  While there I discovered a Kenwood KR-10000 III; the acquaintance says it is fully operational, but I was not able to test it at the time. He has asked me for help in selling it.

Vintage electronics is really not my thing, but I thought someone on this forum might have suggestions where to start.  I will of course plug it in and hook some speakers up, check for wear and tear.  The receiver is located in Southern Maryland, so I could approach dealers in the DC area.  Or are eBay/Reverb/Audiogon the best options?

Anything else I should consider, either for testing or selling?