Good morning Keith,
Before you buy from Amazon try this link:
https://www.ebay.co.uk/itm/Grease-Gun-G-Coupler-Quick-Release-Lock-On-Coupling-End-1-8-BSP-Workshop-Farm/163660375854?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
I bought one from these people, it was brand new, less than half the cost £6, arrived in a few days and it had a 1/8" BSP thread which fits perfectly.
Hope this helps....
Rob.
Last edited by BLUE+4; 31/10/19 12:47 PM. Reason: More information added.