This was definitely one of the most rewarding refinishes I've done to date. Although on the back of the domed case there is a broken area the rest of it came out beautifully. I'm not sure what type of wood the base is- the top is just a veneer but it did develop a nice rich color when treated with a bit of linseed oil.
The machine needed a couple parts to be functional and fortunately I was able to find a 1927 model 99 on Ebay. Once they were installed I took the machine for a test drive and was completely amazed that it sewed perfectly: no tension issues, just perfect, evenly spaced stitches. I was anticipating the need to bring it to a repair shop to work out any issues but evidently that isn't going to be necessary.
Talk about being built to last!