Now remember that Erics'wife (or somebody who is always in his neighbourhood) played the guitar. It was a small group sitting there at -I think- the Parisien. I was indeed tinking about the accordion you described some time ago, so I tried to read the brand name. I thought it was an Eric Martin, but mayby I was mistaken. I tried to read it from a distance. It was a real nice light wood with -I think- black stripe of wood on the keyboard.
By the way, your brothers' accordion is very simular to mine, has the same 'miscouloring' on the wooden parts that are on the top of the keyboard as mine.