Awesome pictures and several of the bikes i acctualy owned and all for quite some time. I had a Kawasaki Z1B 900 a 1975 model in like a Light browny cram and brown liverey, I am not 100% but think the Orange one is a Z1A model and earlier , But its hard for me to tell, because it looks badged differently, i though ours in the UK had just DOHC 900 on the badging. But time has blurred things a bit.
Never had a titan 500 but did have a latter T500 model in red / gold .
And the MB5. Yes i had one in the late 80s, was a £20 abused but running bike, i tried to comute on for a wile, but 30 miles each way was slow even when it was deristricted, i did a few mods raised the exhaust port and bigger carb jetting and Home rolled expansion box, it raised the speed fine but it was not long before it niped up one day and the damage was done, Rather than repair the 50, i found a perfect H100 engine for £10, and from what i can remember was a straight swap wiring conections might have been diferent but i know it was very simple install. I used the home made expansion box with a slighly longer section welded in, and carb from i think an MBX 125 with bigger pilot jet i used , i remember doing some fork emulation mods and dropping them in the trees a little to help it turn in better and to be honest it handled very well for a small bike on pirelli tyres i had on it. I saw 84MPH on that 100cc one cool night and the motor generaly was stock with no porting. Thanks for posting.
PS whats the blue honda in the titan pic? Is it a CB900 or a CBX 750 or some kind.