I find the K&S brass has been hardened, while copper electrical wire is usually in a soft condition.
Whenever I throw away a piece of electronics I check to see if there are any transformers inside. If so, I will take that off and scrounge the wire from it. Small diameter enameled copper wire is getting hard to find, as electronics as a hobby is dying.
Lacking that source (although I have a fairly large supply on hand, craft stores have a fair supply of fine wire in their beading and jewelry sections, in both hardened and soft condition, and in a variety of finishes. They also have a silver thread that looks a lot like Aerequip hose for smaller scales.