Tachihara bellows

The bellows appears to be a bit long on my Tachihara as you can see the sag. Would it be stupid of me if I tried to glue 4 or 5 pleats to the rear section to shorten it or should it be removed and then shortened? Or just leave it.

I'd leave it... you need flexibility in folding the camera, and 4 or 5 pleats glued together would reduce this. If you're concerned with vignetting when using a long lens or in close-up work, you could raise the bellows by putting something under the sag when you expose. A good old rule: "If it ain't broke..."

Many cameras have bellows with a ring on a tab on the edge of one of the pleats. This fits over a pin on the back to shorten and tighten the bellows when sag is a problem. It wouldn't be too hard to rig up something like that for your camera. Alternatively, you could just prop up the bellows with something when shooting; a sponge or the like comes to mind.

Best,

Doremus