Hi,
The only difference is the landing gear; the original kit was designed for retracts and you will find the parts in the kit to install retractable gear in the wing. The later version simply added a small instruction sheet and a few parts for the fixed gear configuration. I’ve built one of each version, but I modified the retract version for fixed gear. Great flying airplane. I think I had close to 2,000 flights on the pair of them and I plan to build another one.
Good luck with yours!
will