fiddle

...Of harpe & of salteriun. of fiðele & of coriun...

1693, John Locke, Some Thoughts Concerning Education, p. 208:

Says Bevin: 'I want peace... and we shan't get it unless we deal with one another as friends. I will be a party to no fiddles.'

That parameter setting is just a fiddle to make the lighting look right.

The meal is served on special trays which slot into the arms of airline-type seats of the passenger coaches. The trays have fiddles for each of the plates, cups and glasses, and the crockery is so well-designed that it is seldom any of the contents get spilled.

Done at a fiddle.