Seat Terra gear linkage

In the past someone has bodged the gear linkage knuckle joint, now its broke. Seat dealer managed to obtain knuckle joint, but when I took it in, turns out someone had sawn off the forked end of the link rod to fit his bodge!! SO now need the link rod from gear change lever to gearbox-& it seems they are unobtainable for that age.1991, H reg. Am told that parts from other Seats & Fiats should fit, but don't know which models & where to find. Any suggestions would be v.welcome. Sun is shining, & poor little motor sitting outside unable to go anywhere!!
Cheers, Al.