Atco 12 36 - not much info out there - need help!

I posted first on an old thread but have realised that this may be long dead. There is not much out there on the net re Atco mowers I am hoping there are a still a few experts and enthusiasts around who may be able to help
I have just acquired an Atco 12 36. I wont say I am restoring it, as 'reviving it' would be more accurate. The engine now runs again (starts better without water in the tank & with a clean new spark plug), the cutter blades are now sharp and the deck and everything else has been wire brushed, ku- rusted and painted with hammerite. On the downside, there is no electric start and no reverse for some reason (- braking also achieved by switching off the engine!)
The next step is to do as OLDYELLOW (some time back) and acquire a powered grass collector and then disturb the spiders nesting in the back of the tractor to add a new pulley belt and find out how to drive the collector.
I don't have a manual so can anyone out there help with answers to:
1. What makes those pulleys at the back turn? (yes I know its a pulley belt..! - there is no belt on mine and there must also presumably be a lever to actuate the drive?)
2. How do you attach the Atco grass collector (when you find one...)
By the way the engine supposed to surge in the way mine does, like a pulse every second? - (single cylinder effect presumably?)
If anyone can provide a pdf of a manual that would obviously be much appreciated. Thanks in anticipation to fellow fans of the little green machine.

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