My advice is to look though the talkbass classifieds and then post a thread discussing the actual bass. That way you’ll get everyone’s opinion on the specific item. Also , this is a bass forum so the seller will not be clueless about his bass, and it’s very likely that you can negotiate the price, specially since the other option for the seller is to let go for 50% asking price to Norm, Grun, etc.
Now about your specific need of it being pre-cbs. Give the 70s stuff a chance. I have sold every pre cbs bass that I’ve owned , and I’ve kept a few early 70s ones as thats where I’ve found the sweet spot according to my personal taste.