Hi Stewart
That looks worth a tenner of anybody's money
. If you haven't done so already, it would be sensible to put a drop of 3-in-1 on the arm pivot points. I'd also check the table for squareness to the blade by making a cut in a 3-4cm thick piece of timber, then inverting it and seeing how the cut lines up. Never trust the saw's own gauge! I can't see a speed control on the saw - is it single or variable speed?
I can't tell what sort of bellows the saw has but it could be worth taking a photograph. If you send the photo to Hegner UK, they might be able to advise you if they have a replacement which they could let you have - there's no harm in asking. If you can't get a replacement you could always hook up the blow pipe to a shop vac instead.
On the whole, I'd say it's worth getting the bellows repaired or a substitute installed for two reasons. Firstly, health; you can get fine dust generated whilst cutting which a blower will push down and away from you. Secondly, without a blower you'll find it difficult to follow the line you're cutting because dust will accumulate over it.
One of the shortcomings of most blow systems is that they are powered by the movement of the arms. If you're operating the machine at a slow speed, you might find the dust clearance to be inefficient. The only exception to this rule that I've found is the
Diamond, which has an independent electrically powered blower. If you were to phone Doug Woodward, I'm sure he'd be able to supply you with the necessary bits to adapt your machine.
Gill