The tractor broke one of its drive /motion belts, in the process of
investigating that, I found another issue..

The PTO clutch driving the cutting deck is not fully engaging, I assume
the clutch slipping. I had an idea something wasn't quite right
sometimes, when asked to do a lot of work, but now I know its slipping
when its supposed to be fully engaged.

The PTO pulley/clutch is an MTD 717-1787A - this one..

http://www.ebay.co.uk/itm/14778-REPL...AMXQWzNSm~w 6

https://tinyurl.com/yb8gqz5b

Which is shown in the photo inverted. The small pulley goes uppermost,
driven all the time the engine is running. The lever coming out of the
side engages and disengages the drive to the larger deck drive pulley.

I have not got the unit off yet, to take a proper look at it, but
wonder(as these are quite expensive) if anyone might have refurbished
one of these clutch mechanisms?

The pan shaped part with the lever coming out, obviously remains
stationary, but I haven't yet worked out what prevents that pan
rotating.