You've gone so far Tony, why risk undoing all the hard work by putting the old belt back on, having it break on you, stuffing a piston or two up into the valves and having to take the engine back out again?
When mine was changed about a year ago the kit was £119.00. I know that it's adding yet more money to an already expensive job but changing the cam belt is far from easy with the engine in the car in any case.... it's so much easier whilst you have the engine out and then at least you have the peace of mind that it shouldn't need changing again for another 72,000 miles
Also, there is a reason why they sell a timing belt kit complete with idler and tensioner pulleys..... and that's because they are also ready for changing at the same time as the belt because if they fail you still risk doing damage to the engine if the belt isn't tensioned due to a pulley bearing collapse, starts skipping teeth and throws out the valve timing.
So Tony, as you will have gathered, my advice for what it's worth, would be to swallow hard, give the plastic card another hit and give yourself complete peace of mind and the satisfaction that you shouldn't need to spend any more time or money on the engine for quite some time.
Martin