The remote control is my own development. Is not possible to use any standard remote and receiver. This would end with massive modifications of the R2R.
My first priority was to make an remote control but to mentain the original R2R unmodified. Only original unmod. vintage gear is worth for collectors.
So I developed an very special receiver which match perfectly to the RT-909 and can be included without any mods. And no soldering necessary, just one wire to get the 5V Vcc !!
Working now on the new receiver version this will be 100% free of solder activities - also the Vcc wire not neccessary. It is not easy because 5V Vcc is not available on the switch PCB of the RT-909 - but I have an idea how to generate the voltage...let's say "from the air"

The receiver is included like an add-on - click-in module.
Because it is a very special thing it is also expensive to be produced.
Sure, there is also no hole or damage on the front plate for the IR eye, but the IR eye is inside of the deck, not outside !
The case of the hand sender is now just an trial, made from an old remote case. But I am not happy with. I am looking to make an proffesional case but is again expesive because of the quantity I have to produce (min. 1000 pcs.).
This qty is a lot and a huge investment but I think is worth to be done.
My idea now is to make an hand sender in the form of an credit-card and 3.5 mm thin.
What would you guys mean about such an hand sender? to modern for an R2R when it is in credit cad format or would be better with an regular plastic remote case?