I'm in a similar situation. The adjuster on my rear left wheel broke and bounced around while driving out of town and the shop and I are trying to find a replacement. Did one of the isuzu adjusters work for you?
I wasn't familiar with this part before but I'm seeing it called several names. The mechanic is calling it a parking break adjuster but this post with helpful pictures calls it a star wheel adjuster:
viewtopic.php?f=5&t=12443&start=20#p97667Either way, it is definitely the cylinder with the gear wheel that needs to be replaced. If anyone has a line on a replacement or tips (alternate names?) I'd be grateful. Thanks!