Mike, I'm just gonna disagree with Charlie, mainly because I'm in a disagreeable mood or maybe because I had a 4 stroke 75 hp on the Jenny B and was extremely satisfied. Given that the early Evinrude you're looking at is probably a 2 stroke, it's lighter weight puts us pretty even in the power department.
As for outboard hours, it sounds like the hours are reasonable given the age. I was lucky and just bought my C-16 with a 1993 Mariner on it and the hour meter was a totally believable 156 hours. If the compression is good and it's been serviced regularly you'll have 2-3 years before facing a re-power option. By then you'll know one whale of a lot more about your ride and your style of boating, which will be invaluable when it's time to choose your new outboard.
One has to remember and repeat OFTEN that the C-Dorys are not ski boats, racing boats, drug, or illegal alien running boats. They don't even like going faster than about 30 knots. The C-22 was designed around a 75 horse outboard. 5hp under that shouldn't be a deal breaker. 25 hp under that would be (IMHO) unless you got it for a price that left room for an immediate re-power.
Don