My wife and I purchased a new "Thomas" 30-button D/G anglo concertina in 1991. Periodically, I have looked for information about the maker and other instruments of the same provenance, but I never see these concertinas mentioned on the web (nor, as far as I can tell, in the searchable archives of this site).
If anyone knows of this maker, I would be fascinated to hear about him or her. I was told the instrument was made in Wales, but I do not have documentation. The