When my father built this house, he over-economized on the water taps (faucets), resulting in a mix & match of at least three different brands that won't mix & match because they are not compatible. They are all out of date, so replacement parts don't exist meaning that all will have to be replaced, along with light fittings, power outlets...
With gravity-feed hot water, the weakest link in the system is the shower. Twist the knob that 1/64 of a degree too far and suddenly the cold water is pushing its way up the hot pipe---not an ideal way to have a shower.
I noticed that the bath tub outlet didn't appear to be so restricted, so I connected a $15.00 washing machine drain hose to the spout and then slung it up over the wall into the shower recess.
The yellow "shower head" is my flat-mate's addition. It started out life as a pressure canister on a super-soaker. Stabbing a few holes into it with a soldering iron created a nice low-pressure head. The fringe along the top is where heated pliers were repeatedly used to press and tighten until the head sealed with the hose.
It ain't pretty, but it works, and we can all have decent showers at last!