Hi,
Hopefully these will help you!

If you still have original needle and pipe with lock spring and two nut, these should be usable with throttle barrel. The felt washer is necessary too!

I have done this to Webra Winner, which is quite similar as Record. All the important measurements are in mm and as accurate as possible from my own Record engine.

Only the throttle arm is somewhat draft, but I think it is adequate this way.

Best Rgds,
sjhh57