Howdy Sedanman,
That strange name you have there should be Jobu, which was a Norwegian manufacturer of good quality units. They were bought out as part of the Electrolux aquisition assault, and off'd immediately.
The balancing piston McCulloch, was the very rare indeed BP-1 McCulloch. This saw had a huge number of radical innovations, many years ahead of their time! It used a topsharpening scratch type chain and had a powered grinding wheel behind the drive sprocket. The thing cut like a banshee! Problem was, the supercharged engine would hit 15,000 RPM, and this was a McCulloch. It would run like hell for a short period of time, and then grenade seriously. McCulloch made a serious attempt to get everyone back, (which is why they are rare) and buried them in a big hole, and filled it with concrete! A few people saw McCulloch comming and hid the saws in basements and holes in the ground, until the coast was clear. This was the source of the collectors remains of this model. Literally, McCulloch representative went around physically retrieving these!
The tree jack air bag was marketed by Jonsereds for a while in Europe, but only a few were sold in N. America. The problem was our guys would saw into it, or try to use it to throw a 6 foot diameter tree. The thing was intended for the little squirrel ladders in Scandanavia, it just did not have a prayer over here.
The saws from Russia would be Druzhba, first made in the mid '50's but continued unchanged up to date. They were made for use in Siberia and China. The only other Russian saw was later, and was the Ural, which was an exact copy of a Partner P100. The other saws in the East Block were either western saws, or TOMOS made in Yugoslavia licensed from Husqvarna. Normally model 65, but later models were tried at the last.
Regards,
Walt Galer