hello

https://www.ebay.com/itm/Universal-Blac ... 3145967062

Is it O.k for the weber carb?

NO that sort of regulator will not operate at a low enough pressure for the Webber
It needs 3psi max or it will flood ,i regulated my pressure by putting a restriction (a piece of smaller bore pipe inside the return pipe then put into a fuel can used a longer fuel feed from the tank on a stand to the pump (electrical pump)and measured the pressure at the end of the fuel feed pipe removed from the carb .The restriction I used had a 4mm hole in it although the pressure SHOULD be rechecked with the tank in place and the return pipe connected to the tank

So Jed, just so I'll be sure I'll understand:
In the attached Drawing, in which letter you added the 4mm pipe?
Where you put the pressure gauge?
I presume the question are due to bad English understanding, THANKS.

That's the wrong picture. The setup with the loop was used in case the tank had no fuel return connection. However also that setup used a Dell Orto jet (size 60). The jet is positioned in the second (left) Y piece in the exit that goes into the loop (or to the tank's fuel return connection). That restriction is not to reduce fuel pressure but to make sure that the fuel return to the tank does not cause the pressure to drop too much.

as already said the diagram is not quite correct but using your diagram the restriction/jet would be in the pipe between the Y piece on the left and the Y piece on the right between the 2 D pipes the pressure gauge would be placed in the end of the pipe D after diconecting it from the webber which should read 3 psi with the pump running