VO Zeppelin fenders. as KC8QVO said, they take a little bit of work but will last forever.
my set of SKS mudguards I bought in the 70's, and have been there ever since,
are still in fine shape.. ..
the bus rack hook will pull over the hoop of a low rider rack too ,
its just the tip of the mudguard that will get pushed onto the tire, will it work , as a repeated use , is unknown
I ran my front mudguard far enough forward , (actually, a 2nd rear) and attached it to the low rider hoop.
Then I noted the situation.. ... just thought I'd share my observation.
Note, no safety breakaway strut fitting on those(ala VO) type of mudguards ..
sticks can jam in the space , bend the strut and stop the wheel turning.