Vintage ROBERTS 770X Reel to Reel Parts - Selector Knob

It has the set screw.

Roberts Electronics 770X Three-Speed Reel to Reel Tape Recorder Manual

Roberts Reel-to-Reel Tape Recorders for sale

Roberts/Akai Preamp Mod

Akai Stereo Parts / Spares for Vintage gear.

1965 Roberts Model 990 Stereo Reel-to-Reel Tape Machine Recorder w/ Tube Microphone Preamps Mic Pres by AKAI 997 4-Track

Roberts 990 Vintage MIJ Japan Reel-To-Reel 2-Track Tube Tape Recorder Analog 1/4” Stereo Machine Gray Suitcase Matching Mic Pres PreAmplifiers R2R by Akai M-7

Vintage Roberts 770 // Reel to Reel / Built-in Tube Amp / Service Manual – AURAL HiFi

Roberts 770X Reel To Reel Analog Tube Works Great!

Roberts 770X FOR SALE! - PicClick