So…. I’ve added the slider switch as suggested by Paul to my turnout, and it works great. It locks the point in place and changes the polarity.
As you can see from the photo below i mounted the switch sideways to test it. Drilling a hole in the knob and connecting to the tie bar with 0.45mm wire. For the electrics i just connected the centre pin of the switch to the v and the outer pins to the rails.
I swapped the tiebar for a longer strip of PCB to provide room to drill a hole. As Paul says this does prevent the switch rail from rising.
I did get stumped for a while when i found i couldnt isolate a train on a section of track when the points were turned. I eventually found that there is a metal pin within the plastic slider switch which made a connection between: the rail, the tiebar, my control wire, the metal within the slider switch, the centre pin and the crossing v. Arrhhhhhhhh. To solve this i scraped back the Cu on the top of the tiebar. This had me flumoxed for ages, i just could not see how a circuit was being created!
Stuart, one thing i’ve noticed with my construction is that moving the electrical switch with my finger works well, but moving the switch blades directly works less well as the electrical switch is more ‘sticky’ and neither the switch nor the points latched. I suspect it would be better if the rails and switch are propoerly stuck down, and with a thicker (0.7mm?) wire. Everything in the picture is stuck down with Pritt or bluetac.
However i did see an alternative solution on youtube last night. See option2 in the link https://youtu.be/hjeNJiOFEgg?si=2dDzXXgyzvU3pBBW
This hides the switch under the base board, which might suit what you are looking do…