The previous owner looked to have installed (and subsequently removed) an after market windscreen washer. Currently I've got the nozzles installed and some tubing connecting them, but there's no bottle and pump system.

I wanted to get the period correct bottle (Mini is a 1969 K), but I'm torn between a manual pump and a discrete electric pump.

My car is far from original, but hoping to keep it within the realms of being period correct.

I think I've done what I think you are trying to do.
I have the original reservoir bottle in its position (new and still available), with the original tubing and non-return valve at the bottom of the bottle.
The standard original nozzles in place. (Modern replacement nozzles do not have the small brass swivel balls to direct the stream.)

In place of the original manual plunger I have a Lucas style spring loaded toggle switch on a short stork on the lower dash rail controlling a "suck and blow" pump.

Most washer motors are intended to be located under the reservoir so they can be gravity fed but there are pumps that can draw up water and pressure feed it out.
I have fitted the pump to the peddle box. Needs a power pick-up to the switch and pump.

Can send you photos.

In my previous 850 I pulled apart the genuine manual pump and fitted a push button switch inside with the cabling coming out where the tubing would normally be. In the engine bay I hid a small 12v pump which when activated by the manual pump switch drew water up from the factory washer bottle.

_________________
Your silliness has been noted.

Scott
Copy cat

Seems an original style bottle with an electric pump is the go.. thanks all