Don't know too much about the Globetrotter - 'cept it's cute!
Biggest issue for me was the axles. After performing an inspection, I verified they needed to be replaced. It wasn't a difficult job - but heavy! Mine included new brakes too. Thankfully mine had new tires - but be sure to check those too. They can look good on the outside but be rotted. Search this forum for lots of info on that.
Here's a link detailing how to determine the status of your axles: http://www.inlandrv.com/articles/dur...xle-92001.html
One surprise I got after getting my '73 is that it doesn't have a grey water tank. Maybe the one you're looking at has had that added! Some campgrounds haven't seemed to mind me letting the dish/bath sink water drain out. But, at more populated campgrounds, I pull out my portable waste tank (a Thetford SmartTote) to contain my grey water.
You might want to check the gaskets. These are the black rubber gaskets around all the windows, door, vents and access compartments. A tedious but simple job to replace. Mine were all smushed and cracked.
Oh yeah, you might want to search this site for "rear end sag". It seems to be a common issue in a lot of the trailers from the 70's, et al. Mine might have a tad, but I'm ignoring it for now.
Good luck! Let us know if you get it.