Wow! Did I ever get lucky!

I ran into a gent who owns a Bacchetta Strada and was willing to lend it out to me for several weeks. It's now sitting in my garage. I can't wait to try it out tomorrow.

One problem: the seat mount is stuck on the tube. I'm pretty sure it hasn't been moved for at least two years. Any tips on how to loosen it? I've spent a while on the mechanics forum and not found anything helpful.