Many thanks once again, real helpful information. I dropped Roger a note a year or so ago looking to purchase two alloy cylinders and mentioned to him that I was or just had retired and that I was trying to build a workshop, so that I may do some of the machining myself. I have a fairly good quality lathe and I am looking for a small milling machine. I spent many years in project management, sales and service business's but my background and original training was as a scientific instrument maker, serving as an apprentice at the Imperial college in London. The down side however, is this was a long time ago, so I will have to bring my self back up to speed with not just the machine but also the fabrication of the exhaust systems. Really interest to know how you get on as Ellis is quoting figures of around £400 + for four gears and £600+ for six gears.
On one of the documents that I have printed off from this forum is indicates the use of a needle roller HK1516 is this what you are using on both ends of the layshaft.
At the moment I have the 8inch front wheel hub in the lathe so that I may clean it, unfortunately I cannot gripped it on the outside and have just managed to hold it on the brake plate side.