That is very modern to me but looks a bit funny.
Here is a site with authenticated sigs with which you can compare it.
Quick peek at that site shows an obvious secretarial Gleason which is, or was, just on eBay.
This piece looks fine. You have to keep in mind that Jimmy was a regular Trek convention attendee for 30 years, his earlier signatures were much fuller and with a bit more flair. The last few years of his life he was pushed into shows in a wheelchair and hooked up to an oxygen tank. Later signatures were kind of smooshed together like the one in the original post.