Beeman 350/Diana 6m air pistol

I'm looking to rebuild this pistol but so far I haven't been able to find any info on how this gun comes apart. Rebuild parts are available, seals and springs, but very little rebuild instruction. Without some instruction trying to take this one apart wouldn't be a good idea since the main parts have long been discontinued and are hard to find. This is a dual action gun, no recoil, with cams and two gear racks. It needs to be done correctly the first time or there might not be a second time. Has anyone tackled this one before? Thanks.

Hotair