That is a pretty deep looking cam compartment. The cams I have seen for Dressmakers have tall top hats on them and are not the flat style so maybe that is why it is so deep as it needs room for those taller cams? Maybe that will help you to decide which cams to buy to try out.
Neat machine, I like it
a lot. Sometimes you can never find a manual so you buy one from Sewusa that is the closest fit and fiddle with the machine and take notes until you figure it all out and then add those notes to the manual you have. Of course the very next day you will find the manual at a thrift store for 10 cents!!!
Also check to see if sews without a cam, some will only do straight stitch with out the zigzag cam.