Working commercial, MRO and corperate. I have never worked for a company that wanted us to have any personal calibrated tool. Keeping up with calibration is a task in it's own not to mention the expense. Not to say that many guys don't keep a fluke on them (for reference only). Otherwise a set of light hand tools, no sockets larger than what is in a 1/4" drive set, generally no wrench larger than a 3/4". A pair of "flush cut" wire snips are nice usually found in sewing/fabric stores. A butane iron with a torch adapter is great, just don't get caught with it. Plenty of self made stuff like jumpers etc.