Jimmi I'm not sure if anyone is reproducing them.
I'd imagine most second hand ones will be pretty worn too,bearing in mind the youngest ones are the best part of 60 years old.
I kind of sidetracked onto other things on the truck,but i'll still have to get mine working a bit better,although it did improve slightly when I filed/sharpened the biting edge of the bar.
Maybe you'll get lucky and find one from a truck who's owner parked it in gear rather than using the brake pedal......
It might help to re-post this in general truck talk as it will reach more guys,not everyone checks in here.
It's not really a Hi-Po question,more of a general truck querie.
I'm sure we're not the only ones......