A common fault on Talbots was the linkage dropping away - a metal ball in a nylon socket. In some cases, the nylon wore down & the link dropped off.
Mine was 6 months old. Whilst it was in the garage, another bloke was there with the same problem in a 1y/o motor - except he lost the whole linkage whilst hurtling down the motorway.
When mine went I had 1st & 2nd. 3rd and 4th were in there somewher but I couldn't find them.
Within 3 months it happened again. This time, instead of limping home in 1st/2nd, I scrambled under the car, clipped the link back & wrapped a bit of coathanger wire around it in a figure of 8. Sold the car 10 months later with the wire still holding.
May be a similar problem?