Enstrom
Oh and I forgot .... the original two 40 USG capacity fuel tanks always had the transparent 'boiler' guage for external fuel contents readings. Usually marked 60, 120, 180 and 240 lbs. The problem was that in service the transparent strip became opaque over time so many simply got painted over. Contact the Steve Payne Roberts Enstrom support engineer. He'll send you a standard wood 'dip stick' on request. Or make one yourself using your own graduations! Safe flying. Dennis K.