I have collected old fashioned knurls over the years,and letter stamps with serifs. Nothing looks worse than to make an antique looking piece and diamond knurl it(they DID have diamond knurls even in the 18th.C..They just don't look right to me). Sin #2 is to use modern,plain GOTHIC stamps. They just RUIN the piece. If I could not find OLD stamp sets(I make them sometimes),I'd AT LEAST make a teeny straight chisel,and add the serifs as a must. The biggest problem if you can't find old,artistic stamp sets,is you don't get the beautiful 5's,2's,7's,and 6's that some of them had back then.
My favorite set must be nearly 18th.C. at least,maybe older. It has true Roman letters with thicks and thins as well as serifs. The stamps are made of crudely rolled steel,with 2 flat sides,and 2 bulged sides,from primitive rolling. AND,the striking ends were left angular from being hot cut off with a chisel. It was left to the user to grind them square. The set was never used. Typically,tools like saws were supplied unsharpened,and chisels were supplied un handled. They were frugal back then!!
The brass dividing plates are actually that deep gold color from aging. I NEVER touch the outfit without nitrile gloves because the color has developed so beautifully. I made that outfit in the 70's for my 6" rotary table,which I still AM FORCED to keep!! Have larger ones now,too.