I can't find my proper tape measure so had to use the missus' sewing one lol but this is more like 121 mm, give or take a mm or so. I could be wrong as it's tricky to measure off the panel but judging from the size, I think the bit you've got is the middle mate, as available here:
http://www.customandcommercial.com/vw-baywindow/baywindow_deluxe_parts--and--accessories/deluxe_parts_front_badges--and--jailbars/genuine_vw_side_middle_side_trim_1195mm_used_68-79_8263/" onclick="window.open(this.href);return false;
Just realised (thought I had it but checked my parts tub) I'm also after the short rear bit that curves around from the tailgate to the side, if that makes sense.