I found a cool site with some interesting info on the Royal typewriter model 10, which is what I have. Check out the Virtual Typewriter Museum for info on this and other makes of antique typewriters. 
While I love mine for sentimental reasons, using these oldies is a tough job; the keys are far apart (at least for my fingers), work to push down and not exactly ergo-friendly. All that said, there has been a resurgence in vintage typewriters – old portables can be a warm commodity on eBay.
As for machines like my old Royal 10, which was built to last rather than to carry, consider it more decorative than user friendly.