There is 1 *I*H*A* bassoon in the Hichwa-Rachor database. Nothing is known about this maker except the maker’s stamp on this bassoon. The stamp is difficult to read, and the “A” could be a “P”. This would therefore possibly being the same maker as I.H.P.-O-Basel1956.604.
IHA Bassoon Literature
Jansen, Will. The Bassoon: Its History, Construction, Makers, Players and Music. Frits Knuf, 1978 Vol. 1, p. 406.