Re: what year is it?
6R72D indicates a 1972 motor and I'll verify that! Your paint color should be light green (previous green was the darker Forest Green) and the cover should be white with an orange and black decal on each side. The orange decal should have the numeral "6" and the black square should have the seahorse logo. The word "Johnson" will be in black lettering.
Johnson celebrated its 50th anniversary in 1972, so some motors have "50th anniversary series" on the front of the hood. I don't think the 6hp models did, though.
I would consider $200 for a well running and good condition 1972 Johnson 6hp to be a good price. One thing I would do, unless the previous owner told you that it has been done recently, is to change the water pump impeller. The motor also has a thermostat in it (port side of head at the top, look for triangular cover with 3 bolts), so you should verify that it is working properly.
Nice motor - have fun with itt!
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