Thanks @SCUBA King that's good independent proof the files should work.
I've just ordered a gal16v8-25 to try again myself as i used gal16v8-15 previously..... though I'm starting to think the problem my actually be my burner not the chip.
Ok problem solved.
I ended up going through each version of gal16v8 in my programmer's software and eventually found one that worked! Thanks for all your help