I Googled Delbar Products and it came up as being acquired by
FICOSA NORTH AMERICA in Madison Heights, Mich. Might try the Google search and see where that leads you. May take a bit of time but if still available the stainless steel arms ARE THE WAY TO GO for sure. Mine have been on the truck for almost 14 years and still look like the day I installed them
Good luck in your search and if you make connections on the Delbar arm please post here for future reference.