I don't think that primus make blowlamps or torches anymore,..they seem more about cooking stoves and camping gear. However, they do supply spares so it might be worthwhile asking their 'shop'…see here;
https://www.primus.eu/store/stoves/
Have you tried using an airline?……..another method that worked for me is to soak the jet in detergent solution (Fairy liquid!) for a couple of days and then blow thru………..a friend use brake cleaner in a cheap ultrasonic cleaner and tha worked for him. You could make your way to the nearest 'good' jewllers and ask them to put it in their ultrasonic for a small fee……
EDIT;……You could ask our good friends 'CupAlloys'…they only supply Sievert but I bet they know something that will help you, like where to get the part or what parts can be used instead etc
Edited By Bob Stevenson on 24/09/2019 17:55:27