Shower woes

(I hope this query comes under the appropriate category - ie plumbing)
=============================================
What has started as, and should be, a simple fix up job has not proved to turn into a troublesome.

We have a shower head fixed to the bathroom wall as per photos:




First question - does anyone recognise this shower head at all?! No one seems to have any idea. Admittedly it is fairly old and highly likely discontinued.

Upon removing the shower head:



and the fixing on the wall is at a weird angle as well to accommodate for the additional housing



Furthermore - upon breaking down the shower head a bit further:



We were hoping that we could get a reductor so that we could order any shower head online with a standardised 1/2" thread BUT
We found the screw-thread was not of standard BPS size - aargh



Even tradesmen we brought this to described it as "a bastard"

So unless anyone else says so, i don't think we can find the right sized adaptor/reductor to attach so that we can use current industry standard shower heads.

I am loathe to consider ripping up the tiling and redoing this - perhaps if i remove the protruding piece of pipe work?

Does anyone recognise it?

Any leads/feedback would be most helpful!

Thanks in advance

Sorry don't recognise it. Look closer at the union that is set in the wall. Pics aren't clear enough for me to make out exactly what it is. You may need to unscrew the angled piece from it ,which is obviously a bespoke part of the shower head ,but the fitting in the wall may well be a standard 1/2 in bsp female thread.if it is you have a lot more options.

Thanks @terryplumb - will do so!