Bearing in mind when I got it 'we' had to recut the top race so it was an inch wide, rather than some daft probably Whitworth size or something.
Anyway, went to screw my Park double sided puller in and the Shimano side rattled about. Swapped it over to the fatter shorterside and and it went in ok, then when I heaved on it some alloy threads came out as well as the tool itself.
What size threads are on those cranks, and where can I get an extractor?
The crank is now probably ruined/knackered.
The current crank extractor threads standard is 22mm, used by Shimano, Campagnolo etc. The other end of your tool is probably 23mm, used by TA.
If your Stronglight cranks are older than the 1980s, then the threads are 23.35mm. So the 23mm tool is undersized and has stripped the threads.