HI Jamie,
Your older S7 clutch should not need constant resetting. I would suspect that you have the same problem another chap had on here some 2-3 years ago. The adjusting screw inside the pulley wheel should have a second screw in the same hole acting as a locking screw. It is 1/4inch BSF which may be a problem to you, but I can sort one out if that is your fault/problem.

As to fitting a modern clutch, it is not all that sinister but it will cost you if bought new, and if you could obtain what you need. The new Myford owners in Halifax (RDG) do not advertise a complete-er assembly which is what you would need. The big danger in buying second hand is that you cannot tell if it is OK until you can fit it. Bushes and bearings wear out, but RDG have those. However, as the previous postings you refered to earlier, the bearings are difficult because of the powerful spring in the countershaft.
You cannot just buy a new countershaft with clutch and (different necessary) pulley, which RDG do advertise. In addition you would need the complete cast iron rocking assembly (which RDG do not have) that the newer clutch sits in including the clutch engagement lever and all ancillary bits on the rocking assembly.
Two covers would need modifying in addition. The primary belt guard outer cover would need a circular cutout (or a replacement inner and outer cover) as the modern clutch needs more space. And the secondary belt guard (lift-up cover) would need a modification to the countershaft cutout as the rocking action shifts a bit and the casting is a bigger diameter over the shaft. Note that a newer cover here is no good to you as it will not fit over the mandrel drip-feed oiler arrangement.
The lower casting carrying the motor – what Myford called the Countershaft Arm – is identical between old and newer machines. Do you have the Myford diagrams for your early assembly?

Dennis

Edited By DMR on 23/01/2013 21:44:26

Edited By DMR on 23/01/2013 21:48:08