i aquired an older, prob early 70s johnson. i've only had mercury's until now. I need a little help iding this guy. Apparently, the sn does not tell you what year or anything. I found the sn only the plug of the block but there are no model numbers anywhere to be found. I've looked 3 times now just to be sure. Is there a way to find the year with the SN or am I missing something?