Metric or Imperial?

[Hair Bear]

Hi,
I was recently watching a video of a chap working on a petrol T20 in France. He cleaned the plate on it and showed it to state 'Hotchkiss'. Didn't give it a second thought until I noticed him use a metric spanner on something.
So, was that just chance, or were French built T20s, and I guess through to the 500s, assembled with metric fastenings?