Have another look at the picture.
That's an idler arm down there, not a steering box, so it's a left drive car, .... which uses a hydraulic clutch arrangement.

All of the gearbox castings are the same with provision for both hydraulic or cable clutch, but are machined differently for use in either left or right drive cars. In a left drive car this hole is not used. Hell, it may not even be drilled but in this case, if it wasn't before, ... it is now.

This is the only version of the A12 that was used in the US, so it seems to be widely known by that designation, but over here, we still got the A12 for many years afterwards, but of course in the revised version of the engine, so I always refer to this front distributor version as the 1200 engine [for obvious reasons] while the later one gets called the A12 in an attempt to avoid confusion between the two types.

Speaking of distributors, this one has an electronic one fitted by the looks of it.

ok so its obviously using an electric fuel pump....

but whats the purpose of this hose thats
cleverly run through the bellhousing?

crankcase breather?