And here is the point of impact on the cover.

I installed "Open Camera"  to my Android phone.
What a relief to be able to take photos in the resolution that fits the forum. Before I had to reduce their size in Photoshop which could take ages.

Thanks Dave.
I intend to drill a similar hole, can't have too much oil in there.

Finn, what sort of carburetor do you intend to run, and what air filter setup?  You will have a free-flowing exhaust and a head that should also flow a whole bunch more.  What are your plans for induction?

I drilled that oil hole in my CCT.  I never find any evidence of oil in the hole, and never find the CCT filled with oil.  It's wetted with oil on the inside, but I never find it filled.  That might be due to the location of my hole.  The plunger overlaps the hole.  It might be better to place the hole at the rear of the bore so that it remains uncovered by the plunger.  The green circle is my proposed location. Regardless, it never gives me any problem and rarely needs any attention.  The 1.5 mm back-travel seems just about right.

36mm Mikuni from Lancer. I turned the adaptor flange out in a straight taper, to join stepless into the 42mm inlet.
The first miles, it will be running a UNI foam filter, but I worry about the sound from that inlet, and will probably weld up a custom filter cage, allu or pvc, with generous filter area, and flow, but also damping the sound. There is extra space for this, with new lithium battery taking muc less space up.

I have taken a big mouthfull of modifications this winter, and need to ride the bike to see what I like.
The Loctite 592 appears to already clear customs this weekend, so I can get the engine together pretty soon, just need to gap the rings,  except the top cover, because the delivery of the rockers has been delayed by 14 days. Anyway, it is still winterlike here so probably fine so far.
So many things I would like to change, put the engine over in another frame, for example. If it could fit into a Yamaha RD350 YPVS frame, I might do it. Byby Bobber boy! But I am rambling!

Dave,
Thanks for your comment about the inlet sound. My first bike was a Yamaha YDS3, and it was infamous for it's howl. I exchainged it with a Kawasaki A7SS, which had the inlet to the rotary disk controlled carburettors, all covered inside side covers, so it had no inlet sound at all. So the prospect of noise from an open inlet had me worried.
The spigot is an easy fix, if you own a 4 jaw chuck. Just chuck the carburettor in the end that mates with the air filter. Center it using a lever type dial gauge, which can reach all the way into the finished part of the carburettor bore. Then mount the spigot, and with trial and error, or trigonometry, turn the surface to start at 42mm and finish at 36mm, at a suitable depth inside the carb.
  I did not flow it.

I may still get to that, flowing the full induction system.
Mike, you bring some good points about keeping the stock air filter boot. Attachment to the side covers and the ignition module is a good thing, and will make the bike look as good as stock. Which is a benefit if I get pulled over by nosy cops.
I never felt comfortable with the foam filter, don't know how to maintain it, but assume it would have to be taken out for regular cleaning and oiling, so I prefer a paper filter. Since the K&N RD-0710 is available here in Denmark, I bought one, and so will have a similar induction system as yours.

I test assembled the clutch today and ran into some interesting problems. First it dawned on me that the only way I could put it together was to assemble the complete clutch (ex the release plate) and insert it as a unit. Then when I get the plates stacked, there is amble room in the basket (I call the exteriour for the basket) the fingers on the outside friction plate are about 2mm away from the front of the notches that they ride in. However, when the splined hub gets fastened to the shaft, the pressure plate is so close to the basket that it rubs on it.
Thus no room for release travel. I felt there were 2 solutions: either skim materiall off the pressure plate and the splined hub, or introduce a 2mm thick washer between the basket and the splined hub. I chose the latter (there is already one washer there) and turned one washer out of stainless sheet. This seems to solve the problem, and extending the release plunger by 2mm (a sawed off disk from a 6mm rod) made the external clutch lever align with the 2 marks on the clutch cover.

I am a bit surprised by this, I am using the DR650 splined hub, as well as the narrow but thick outher friction plate with steed disk and so called wave washer.

Shown is the washer that saved the picture

And here the pressure plate is in the state where the plates are compressed (or almost, trying to do it with one hand and hold the phone with the other.
But I think the plates align perfectly with the basket.
There is no rubbing between clutch and inside of clutch cover.

I know the parts are full of dangerous dirt now,  metal filings and such, i will wash them carefully before final assembly.