Rail mount help..

[Marvin]

I have some rod holders that were mounted on a previous boat I used to have. They were side mounted but I would like to use on the boat rails. I had a couple of these brackets laying around that work great, problem is don't remember where I got them. Anyone know where these could be purchased. They may be possibly from a rod mount, just can't find them..thanks for any help. Here are some pics of what I'm trying to locate.