I'm cobbling together a personalized rig from second-hand parts... I have a few of these, but not enough... these have been perfect, but I have no idea who makes them or where to get them.
Optionally, any vendor from whom I could source piecemeal rail blocks would be a great lead. Thanks.
I'm a big fan of Berkey System though. I use their rail blocks on my Steadicam for my monitor mount. I think they've got a much better hole configuration, and they take up less space on your rods too. Also, the price includes free shipping. http://www.berkeysystem.com/store/60mm-rail-blocks/rail-block-standard/
You may want to not link to a picture on the Philip Bloom forums. To view the picture on here, you need to sign in over there first, and that's not a great thing to make someone do. Just post it as an attachment on here.
Every now and then I get on eBay's camera section and search for things like "15mm rail", etc. Amazed at all the little doodads from Taiwan that show up. There's a guy selling follow focus gear rings for $18 that are the same quality as RedRock's $45 pieces. And he has free shipping.