More thread creep.
Welshy is in the OED, added in the 1987 supplement, defined as slang for Welsh. This supplement also carried Welsh- to fail to carry out a promise or to keep an obligation. This is common in the US and Canada. Is it used in England?
Same sort of slander applied to Scots and Dutch about money.

Jerry, ran across "Old Tan Tucker" in the Bodleian Collection.