As they say, sometimes one thing can lead to another.
I decided, with regard to my weight reducing obsession, to replace existing cast iron rear whell bearing carriers with lighweight aluminium ones. However, as no one appears to make them with lugs to attach a caliper, a separate mounting bracket is also required. Didn't consider this an issue until the bits arrived from different suppliers (neither had both bits available!). Brackets didn't fit bearing carrier. A couple of hours later they did.
I then discovered that with the brackets sitting on the carrier the caliper was 6mm too far out, so the carriers had to be milled so the bracket sat in the correct location.
Then I noticed that the lugs didn't stick out enough, they were short by about 10mm. It dawns on me that these were designed for standard Sierras that use small rear discs! I have now ordered a pair of standard, non grooved, non drilled rear Sierra discs.
However, the original Cossie discs were much bigger than the standard Elan front discs, so this forced change has helped in the brake balancing department as well as reducing unsprung weight by an extra 1.3Kg on top of the 1.6Kg the new carriers have saved.
Next and final step is to get the wheel hubs machined. Two new holes to match the existing along with relieving of the underside to a depth of 1/3 the thickness.
CV joints should be back this week from being lightened so that will complete the rear end and it can be put together.