Can anyone tell me how to identify who built my 70's Japan Masada Performer bass? It is a Fender style maple/rosewood board neck/headstock but unlike Fender, the trussrod extends 1 inch into the body cavity with a hexscrew adjustment and the dot markers appear to be copper. Very nice fretwork in terms of the fret ends and a very good looking curved rosewood board that measures 3/16 thick on the edges and 1/4 thick in the middle. The neck plate is 4 bolt with no 'Made in Japan' or serial number. The body is a maple center block with thin walnut strips and wide ash outer wings with no pickguard. The rest is basically P copy but the pickup is a hotter wound with ceramic bar magnets. I am trying to identify what factory this bass came from. Thanks in advance?