The soon-to-be-released Barndoors are directly compatible with Revision -H and later of the MAC 2000 Wash.
Fixtures with revisions -A through -E require an upgrade of the u-shaped plate to which the front lens attaches in order to receive the Barndoors. (Revisions -F and -G were implemented at the same time as Rev. -H.) The revision letter is found on the serial number label after the P/N field.