IDEAL 5221-90 - old!

For the last year or so I have been downsized and forced to use a smaller guillotine - the IDEAL 5221-90 - it is a legacy guillotine that we always kept incase our main Wohelenburg 76spm broke down. Well, business has been hard for a few years and we had to move out of our 3500 sqft industrial unit - and back to a MUCH smaller space without 3-phase electrics - lucky we still had our old IDEAL 5221-90. We spent a fair bit of money getting the guillotine working again - relays and switches were replaced and it sprang back to life - until about a year ago we had a problem where the small cog that drives the main cog for the blade unmeshed - so when we tried to cut we could hear a noise and see the motor cog moving - but it was about 3 mm away from meshing with the main cog. After much head-scratching and worry - I resorted to calling our guillotine engineer - he really is a last resort but sometimes can pull us out of a hole. - Long story short - he decided that the Cherry E19 switch for the top of the cut needed replacing - I managed to find the last one in Northern Ireland and put it in myself - it worked - or so it seemed - a few cuts later, the same problem happened. Somehow over the next week I managed to get the guillotine working again - it seemed to coincide with me taking the blade out and reseting eccentrics and putting blade back in. Now the guillotine works for extended periods but some days we do a lot of cutting - yesterday was one of those days - 2 batches of business cards, 10k time sheets cut in 3 positions, a digital booklet run which needed trimming after staple folding.... It came off the cog again - at this point, I get a block of wood and push the main cog while my associate presses the cut buttons - this forces the guillotine back into mesh (between small cog and large cog) and Bob's you uncle! However, this time as soon as the blade finishes the cut and comes back to the top the large cog goes beyond it's tooth limit and the mesh is gone.
My question is - is there a way to stop the blade rising so high that the cog goes out of mesh - does it involve bending the aluminium stops that link to the Cherry E19 switch? Is there another way ?
Any help will be gratefully tested and feedback given.
Best Regards
Neil