Had the same dilema...
AD,You asked about specific differences. The MKII model came out in 1986 and here are a few improvements that I am aware of...maybe others can chime in with more:1. "T" shaped cockpit2. updated mast compression post (have read about some issues with the wood support in the older boats, but nothing that can't be fixed)3. updated and larger engine4. updated wiring configuaration behind the AC/DC panel...simplified5. seperate battery storage compartment in stbd. settee6. a cosmetic change with countertops updated to white laminate vs. "wood" color.7. line controls for reefing brought to the cockpit8. improved traveller to "flat" track from curved and better blocks - Garhaurer9. choice of a wing keel...if desired.Your next question was "is it worth it"...only you can answer that based on how important these features are to you. For me, a wheel, "T" cockpit and walk thru transom were important, so I bought a 1992 model. Either way, you are going to have a great boat. They all sail pretty much the same and are solid...the only differences are the features. As others told me (and I agree) buy the best conditioned model that you can find... and get a good survey!