Seeing how much Trek 620's go for on eBay and here around Chicago, seems like you should be able to flip that bike for enough to money to buy another, just as good but not quite as sought after vintage tourer that actually fits you, along with many of the other things you'll need (racks, panniers, fenders, etc.) Could probably get $400+ for the Trek in good shape, while you see Univega, Panasonic, Nishiki, and other touring bikes of similar quality and vintage go for $200-250 regularly.