We just replaced our "J-Lock" on our 2004 Cub. Had a time finding the J-Lock. I contacted
Lippert Components Inc 2703 County Road 36, Goshen, IN (574) 971-4100 They gave me a the phone number of:
Topstitch
2727 Industrial Parkway
Elkhart, IN 46516
(574) 293-6633
that carries the J-Lock. I removed the tent and took it to a upholstery shop and they replaced the old J-Lock on the tent and I installed it back on the camper.
They may be able to help you if the manufacture is unable to. My manufacture was unable to help with the J-Lock and I went to Topstitch.