Leitz Focomat 1c Question

I just bought a 1c in very good condition. One small issue is the elevation creeps up. Does anyone know how to adjust this?

Also, does anyone have a 35mm negative film guide mask (carrier) 3x4 cm for sale?

I found the low tech answer. Facing the enlarger the focusing cam is located on the left side where the tension spring is positioned. Elevation creep was stopped by using paper as a shim. All it took was the thickness of one sheet of writing paper slipped between the flat silver plate and the metal clamp or brake. The tolerance is so tight that doubling the paper made it too thick to slip in.