Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I have some metric Craftsman ignition wrench sets that I have been happy with... they came in my larger sets. Sizes included:  4,  4.5,  5,  5.5,  6,  7,  8,  9,  10, 11 mm

If those are small enough, look for an older set in this style bag that says Made in USA on the front:

https://www.ebay.com/itm/Craftsman-10-pc-Metric-Midget-Ignition-Wrench-Set-Metric-USA-made/352926189735?hash=item522c0a48a7:g:~0QAAOSwKKBeFq2w





This style bag is a newer set and most often made in China

https://www.ebay.com/itm/CRAFTSMAN-MIDGET-IGNITION-WRENCH-SET-CHOICE-COMBINATION-OR-OPEN-END-SAE-METRIC/114005176476?hash=item1a8b3cf09c:m:mMmmaBywOsLTvZ9mfv5PgGg





Any smaller and you may consider a nut driver set like this (2.5 to 6mm range):

https://www.amazon.com/Wiha-26590-Driver-Precision-Handle/dp/B000PDOIT6/ref=sr_1_1?crid=11ZE6SDS6CI81&keywords=wiha+metric+nut+driver+set&qid=1579964665&sprefix=wiha+metric%2Caps%2C159&sr=8-1