2 rollers of my MBO folding machine rollers have got damaged. Due to delivery schedule I have not enough time to send them for repairs outside our factory. Till I send them for rerubberising outside I decided to do in house. Can anybody guide on which rubber /PU grade and hardness should I use? How to glue it? Should the diameter of rubber be level /same or more than steel? How much more? Any other tips? Thanks in advance.