I accidentally broke shared copies and want to re link

I was soring out a guitar part. I had used the guitar score template and the tracks came in as shared copies - which I have never used before - one for standard notation and one for tab.

I went through the part playing in the score and getting that looking right. I then started editing the tab - which was a mess.

I was about half way through editing the tab - which is a lot of work - and I needed to add a bar in the middle. Inserting this bar seems to have broken he linked tracks which is a nightmare. Is there any way to re link the parts because i do not want to lose all the tab work I have done.