£25 and they use the same tensioner for just about everything

but, like pringles, once you pop, you can't stop

have you got a new chain?
if so you have to slot the tensioner in BEFORE you put the chain etc in
you can slide the tensioner sprocket arm out, slot the tensioner in, slide the arm back in again (i can't rememerb if there are circlips involved here but i've got one in the back garden i can take pics of if you like later on this afternoon)
just don't push down on the arm or else the tensioner will pop out and you'll be back to fords with another £25 in your hands
jam it all in with a screwdriver (thats why there is a slot just the right size for a screwdriver in the head just above the sprocket arm ) so that you don't explode it beforehand
you also need to remove the bottom cover to figure out where tdc is
once you've done all that, just use the coppered links to time it up correctly
once it's timed up you can remove the screwdriver and then spin the engine round by hand to make sure the marks line up properly agian (the copper links won't but don't worry about that if you've timed it up properly) and after a few revoutions you can hear it going "thud"

i'm sure someone else will be able to put it into words much better than me, i can understand what you need to do, i just can't articulate it very wel

if you can wait till this afternoon i'll take a few snaps and post them up to show you where and what needs doing (assuming you haven't already done it all because you want to put it all back together agian )

be aware that the timing marks line up with the level of the head, NOT where they meet (the little white lines on the cam sprockets)