OSSA, along with Bultaco and Montesa, were the three Catalan Marques in motocross and observed trials during the last 60s and 70s. Unable to compete when the Asian dirt bikes hit the scene all discontinued production in the early to mid 80s. OSSA and Bultaco shut their doors; Montesa, I understand, continues to make motors as a Honda subsidiary.
Apparently, like many other seemingly extinct brands, OSSA has found new life (and capital) and is soon--as in days--to launch a new observed trials bike, in Europe only. I'm glad to see them return.