sidecar for VB

[mick.robinson]

I have recently acquired a [Watsonian?] sidecar chassis for my VB. Can anyone advise on, or does anyone have, the 3 fittings needed to attach it?
Update: I now know it's a watsonian model VG21 chassis. I think i've sussed the front and centre mountings, not sure on the rear lower one: should it be a ball swivel type fitting or a plain rigid one? [I should know all this but one thing i've never had is a sidecar!]