Liquid electrical tape is pretty thick, gloopy stuff, especially out of a pre-opened tube or tin. If the holes aren't too big, I suspect it would probably be effective. I would also consider a suitable fabric paint for wider areas requiring treatment, as the LET can build up the surface it is applied to noticeably which may or may not be desirable. A combination of the two used where best suited might possibly yield best results. But for the corners, where some ability to bridge a hole and retain flexibility is needed, I would be inclined to try the LET, I think as it's likely to plug the holes better. It's nasty stuff, so try to keep it off your skin and not to inhale it as you apply it. The Tomosy book "Restoring Classic and Collectible Cameras" has some patterns and information about cutting and folding bellows from scratch, which is a start. Obviously a replacement bellows is the most reliable long term solution, however in the interim the above would enable you to test and use the camera and consider your options, if you're pleased with its other attributes.
Cheers,
Brett
