As promised, sharing some of the info I received from John Penry-Evans, the British CEO of Ace Aviation, Ooty, India:
Here is our brochure on redrives and other parts. I have also given you a few other files and technical figures. They have been in use for approximately 4 years by many customers world wide. They are designed for up to 55 Hp. They are made from a very high quality. There is a very easy eccentric shaft adjustment. Also the backplate can be mounted upwards or downwards, depending on your configuration. No reviews only many satisfied customers.
Technical description:
Extract from calculation as follows: Propeller maximum revs of 2,500 with a 1:1.8 ratio, exactly what most props are rated at.
Engine revs out at 4,500rpm.
On a PK belt it is rated at a pr of 2.99 per rib, so 14.28 ribs, 14 will be OK as we pilots look after our running gear very closely.
55hp is 41kiloWatt so divide 41 by 2.99 and you get 14 ribs.