Steve, here is what I did for rod holders. The tube under the seat is 1″ PVC thin-walled pipe, I flared the end by heating it for a very short time with a heat gun and then flaring it with the neck of a wine bottle. I made a wood clamp to attach it under the seat. The holder for the rod handle is attached to the locker with velcro since I wasn’t sure how it would work and didn’t want to glue it beforehand. It all seems to work fine however.
I plan on living forever, so far so good.