He is getting his saddle altered: fettling about this and that; does not consider what danger he is in.
I have heard the people here talk of "fettling" the hearth when they mean "clean up."
"condition, state, trim," c.1750, Lancashire dialect, from fettle (v.) "to make ready, arrange" (14c.), perhaps from Old English fetel "a girdle, belt," from Proto-Germanic *fatiloz (cf. German fessel "fetter, chain," Old Norse fetill "strap, brace"), from *fat- "to hold."
fettle fet·tle (fět'l)
Proper or sound condition.
Mental or emotional state; spirits.