If you knew how contracts work in speedway, which you should as you claim to be an ex rider, then you would know that vans, workshops, mechanics etc are not free when arranged by the club.
Try Speedway Service on 01553 829197. you're correct about that model only being made for one year. The studs used to pull out of the top of the barrel before the torque setting was reached sometimes. There might be a link on the Jawa Divisov website for manuals.