Hi Gene,
This is a German type so-called
Pappenheimer Rapier, Thirty Years War, ca. 1630; there are examples known that are dated 1632 on the blade.
A very similiar in perfect condition and retaining its original sheath was sold from the famous Henk L. Visser collection, Bonhams, London, 27 Nov 2007, and now is in the collection of a friend of mine. Please see attachments.
When cleaning the very delicate blade please note that there must be a fine central ridge visible all the way down almost to the tip.
For a start, please use olive oil together with 240 grain sandpaper and work your way down to 600 or 800 grains for the final finish, always with a thick layer of olive oil between the iron and the paper.
Please also note that the pommel and hilt were originally blackened; I would therefore suggest to confine your cleaning action to the blade and just blacken the hilt and pommel by tannin which you should get in any drug store; leave it to dry for two or three days, then put a thick layer of olive oil on both the blackened parts and the cleaned blade and let the whole dry for ca. 6 weeks. You will then get a best possibly recovered and patinated surface, and a conserved one as well; the dried olive oil will stay there and prevent the fingers from getting thru onto the iron surface.
I, and I am sure I am not the only one here, would love to see some pics of the result!
Best,
Michael