Thanks. Should we switch and buy a low pressure pump? My preference would be to find a solution favoring dependability and drivability over maximizing power or authenticity. Are there tradeoffs or is going back to (the right) electric a no brainer?
A mechanical pump is a good, reliable solution which can last a long time. The two on my 1969 and 1970 Fiats are OE from the factory parts and continue to give good service.
An electric pump adds several additional points of failure due to the wiring in addition to the quality of modern pumps which has become decidedly sketchy.
Personally, on a carbureted car I am more than happy with a mechanical pump. I personally would not change to an electric, period.
The other factor to strongly consider revolves around safety. An electric pump will keep running as long as the ignition is in the on or start position depending on how you wire it up. A mechanical pump stops pumping as soon as the engine stops. In an accident you may not have the presence of mind to turn off the ignition switch.
An electric pump can be wired to only run when the engine is running, has oil pressure or be shut off by a major event using an inertia switch. One could choose to do all of these things. The caveat is each system adds a failure point which can sideline the car. There are a number of ways to do this which we can delve into if you are interested.
Regardless of either the above issues, make sure the nipple for the fuel line is secure in the top of the carburetor. On old zinc castings the two dissimilar metals of the nipple (brass) and the top of the carburetor (zinc) can cause the brass part to come out and the pump will merrily spray fuel all over the top of the engine and the overly warm exhaust manifold below.
This can be fixed by intentionally removing the brass nipple and affixing it in a more permanent fashion by tapping the parts or roughing up the parts and epoxying them together.
Watching your car burn is not a fun way to spend part of a drive.
PS Buy a good quality fire extinguisher and place it in the car where you can easily get at it. (A bracket in front of the passenger seat or in the trunk are both good options).