After asking some Q's here and elsewhere ... decision was to use Decking oil .......... and manufacturer was to be Liberon.
I spent some time Goggling & called local trade outlets ... found one company beat all others, and included free delivery ...
Rest Express Unit 1 Springfield Farm Perrott's Brook, Cirencester Gloucestershire, GL7 7DT T: 01285 831668, F: 01285 831697, E: snipped-for-privacy@restexpress.co.uk
I have no connection with this company just want to publicise how good they were to deal with.
For me I was buying Liberon multiple 5L tins of Liberon of Decking Oil .. at £24.50 per 5L they beat all other suppliers.