Thank you HCP.

Yes I do have other wallets on the Mac frOm having tried to restore one that might work. They are all unrelated, when I choose to load a tx from the  Linux wallet. (Regardless whether I open the old or new version of Electrum, that's fine, I can bring up all wallets through OPEN on the Mac

Yesterday I tried to focus and look through them all to see the MPK links between the two computer's wallets.

The Linux wallet, althuogh does not show in the boarder the type of wallet, eg '2fa', '1of2' etc. But when I drop down the MPK from menu, I do see this

     x1/self ............ xpub661 ...etc
     x2/cosigner ....   xpub67z ...etc

In my attempts to create/restore these wallets on the Mac, I have failed, and produced only the following, all unrelated:-

     wallet type (1of2) 
     cosig 1: .....  new xpub6Br...etc
     cosig 2: .....    xpub661 ...etc

     wallet types (std) and (std, watching only)
                      ... xpub661 ...etc

     wallet type (1of2, watching only)
     cosig 1 .......   xpub67z ...etc
     cosig 2 .......new xpub69Y...etc

     wallet type (std, watching only)
                      .... xpub67z ...etc

I'm now thinking, what exactly are the right steps for the new wallet - I clearly don't want the xpub keys marked