I'm looking into buying an older Laser right now to learn on for a cheap price, but just wanted to check something first. The laser I have an eye on is a 1981 production year. I was wondering if there are any major changes between time expanses. I mean, it seems that it's very rare that class changes occur for the laser, but is there anything to worry about in terms of construction techniques from back then? Any input would be much appreciated. Many thanks!