Okay.
I have a Haynes manual on my 2.4L MK2, and the Jaguar Parts Manual.
The vehicle came with the wrong Solex carbs and lines.
I obtained the correct units, with metal lines and banjo fittings.
Finished it up, tweaked it in, and I have a flat spot mindrange.
Idle is fine, wide open is great.

The Royze kits don't have good documentation, and the float valve comes with
two brass sealing rings of different thickmesses.
The carbs had thick red fibre washers, the brass ones I used are the thicker
ones.

I do not have any documentation on what the thickness should be.
Rather than tear them down and try the thin washers, does anyone know the
correct thickness of the float valve washers and/or the fuel level in the
bowl?

I know the vacuum advance is plumbed wrong, but the plumbing is the same as
it was on the "wrong" Solex carbs, and it had no mid-range stumble.

I will be fixing the plumbing tomorrow, see what that does.

Thanks.