That's a repro coupling made from the finest chineseum. They are awful quality, had one myself once.
Get a genuine VW coupler (even a used genuine one, Megabug maybe ?) and if you like, push your red urethane blocks into it before fitting.
Your bolt looks like a genuine one as it has the hole through so you can lockwire it to prevent it loosening.
Mk 2 Scirocco 1600 GT new clutch kit
Mk 4 Golf front brake discs & pads new in box (288 mm)
- Collect for free - I need the space - PM me.