Both the owner of the 375 and I have been aperture sight shooters for quite some time and these will both be sighted with them as are our other Lee Speed rifles in 303. I will definitely be looking for a dust cover for my 400 so I have a light and a heavy rifle with the 303 and want them to both look the same so if anyone has a dust cover that they would sell on I would be most gratefull.
There was a scope sighted Mk l* (LSA) that my fried bought home from the gun show a few weeks back and that had a QD side mounted scope and the dust cover had much of the left side cut away for the side mount. Personally I think the aperture sight is more than suitable for out to 180-200 yds and in that case a scope may just be a superfluous encumberance.
I have used ebony on rifles for both caps and tips for a while and haven't struck the trouble you speaks of as yet. I hadn't been chasing buff horn although I do have a couple of bits that could be made into caps if I was so inclined but will hold off on that till the forend tip can be made from the same material.
While I can do the grip cap in wood or horn, doing the same thing from Damascus is a step further than my inclination goes.
I have to disagree on the use of my full sized router for making the caps as having been in the joinery/cabinet making and carpentry business after starting back in 1967 and even though I may be retired now, I think I have a reasonable handle on what is safe and what is chancey.
The first one was simply a trial and since then a solid plate has been made for the base of the router and with the two pins in the hold down plate the next ones I made were as stable and firmly held as could be had so I will continue to make them like this.