Carb advice please.

[Wight-biker]

I know I've asked for advice on this before but different advice now required.
Well, here's she is.
1951 A10.
1960s Watsonian Monza Sidecar.
Bought as a part rebuilt project due to the previous owner being cruelly taken by Covid.
She has a brand new Pre-Monoblock Amal her that is total rubbish.
Just keeps flooding and leaking fuel everywhere.
I want to replace it with a Monoblock Carb but can anyone advise me of the carb number l need to get please.
I've tried all the advice to stop the Pre-Monoblock leaking and flooding to no avail so its going.
It was already fitted so l can't return it as l don't know where he bought it from.
So advice on replacement please.

mod edit resize and insert pics, remove external links to pics

[CheeserBeezer]

You should have a 1. 1/16" inlet tract so any 376 carb with same inlet will fit. The first swinging arm model with a monobloc was in 1955 which was a 376/1. Prior to that all carbs were 276 type (as yours). Main jet is 240, pilot jet 25, slide no. 4, needle jet 1065. You probably won't find a 1065 needle jet but you can compensate for a 106 or 107 by moving the need le up or down. You'll need to experiment for a while but should find the right settings after a bit of trial and error.

[RDfella]

As it's got a chair, a monobloc replacement would be a poor choice, as the float bowl being to one side can cause flooding / starvation when cornering. Disliking concentrics as I do, nevertheless I'd recommend that instead.

[morris]

If you want to go the concentric route, a 928 will do. Have one on the ‘52 plunger. Works perfectly, first kick starter.
Pilot jet 20
Air slide 3 1/2
Needle jet 106
Needle pos. 2 from top
Main jet 250