The chopped carby doesn't need a float chamber cover. Both carbys have the extended jet block holders and banjos.
I have never heard of using a cover with an inlet, I have seen them but I thought it was a breather. I learn something new every day.
The worst problem you are going to have is trying to do adjustments between the carbys.
I have a 1966 Atlas with a left & right hand Monobloc, it is really difficult to adjust.
My late friend had a Connie but it was a single carb model.
I didn't realise there was that sort of cover with a feed tube either until a friend showed me his and pointed to a source. I wonder if you could use two, as they're cheap compared to the extended jet blocks? (Ah, I see you're asking yourself the same question Slymo.)
Adjustment is a palaver with parallel closely-spaced carbs, I agree. Putting a small hex on the head of the pilot air screw can help with getting a weapon onto it. Is what I have on the 650SS.
I am also told that setting up the cross-feed pipe between the 2 bottom banjos as a rearward-oriented 'U' loop, and then making a longer slow running adjustment screw for the inaccessible carb (unimpeded by the feed pipe), is a good plan, although I haven't done that myself (yet!).
(Not sure if the standard twin-carb Connie used parallel or splayed carbs - if parallel, then the minor mods would probably be wise?)
Apropos the separate cylinders and heads, yup, the one-piece cylinder was a massive improvement (my Oilfield addict-mate who has one also tells me). Oilfield weren't alone in using separate bits though, as AMC did it, with fewer leakage issues. They went to 3/8" through-studs - still only 4 per side, however - on their later engines but even their 650s ran on 5/16" for several years.
Definitely not as solid as the barrel to head fasteners on an A10 I agree - but you win and you lose, as at least there's no risk of breakage of (thin-flange) barrel flanges. That's a painful T-shirt to have to wear, I remember it too well.