So,
got some Gotoh SD90 -SLB-MG-T-B from Philadelphia Luthier supplies. These are black locking tuners and after a nervous start I managed to get the old ferrule part out and the new one in after scraping away the hard glue on the inside. I've just fitted the low E but so far so good.
I'll change the other tuners once the current (new) strings need replacing. They look better (all black) plus they lock AND they more solid with tuning. The tuners buttons are still plastic but the other benefits have made it worth it.
Thanks for everyones help.
Here's a link for others and will send a pic once they are all done
https://www.philadelphialuthiertool...m-lock-traditional-3-x-3-guitar-tuners-black/