That sure is an old girl, probably from the 50's but you can't go wrong with a Sioux. They are the cadillac of valve grinders (that the average guy can afford), and they haven't changed much over the decades . Mine is a little newer but I have one as well, I use it almost every day. You can buy precision adapters for the chuck to accept valve stem diameters as small as 3mm, you'll need one to do anything smaller then 7mm valve stems, unfortunately they cost two times more then the price you paid for everything but when you are done you'll have a real nice machine. Cylinder head supply is where I got mine, you can get new stones and some fluid there as well.
