Agree with everyone else, bayonet #1 is what you need. Many Rollei accessories were of brilliant design, the cases weren't. They need to be pulled outwards at the front to get the camera in, after a while the stitching rips - in fact, I would think you won't find a case that doesn't need stitching. If you want a compact case, the padded pouches made for 35 mm SLRs plus a small zoom lens are great for a Rollei (possibly upside down) - the case will fit on your belt if necessary. The regular leather cases are not dust- or rainproof and don't provide much protection against knocks either. I have also never used a lenscap (except when sending a camera for servicing). If you really want to use one, there are 2 kinds - one is a one-piece item made of hard rubber which is guaranteed to fall off the camera, the other upmarket version is metal and of two-piece design, the two pieces being connected by a hinge. This bayonets into one lens and then turns and snaps into the other. If you want a lenscap, this type will at least stay put.
Regards,
David