IIRC = if I recall correctly. This is a fairly std internet term, although I usually feel ridiculous using it.
For oddball sizes I had dies which you could replace and adjust the individual cutting bits. I simply moved the bits with the correct number of teeth into a larger die. You don't buy those sets at princess auto mind you. Failing that you could always go (where else) onto ebay:
http://www.ebay.com/itm/1-16-UNS-Rig...item2567a85612
http://www.ebay.com/itm/1-16-UNS-Rig...item5ae28800d0
Also, instead of using pipe, try using actual conduit. Easier to bend and it's the correct outer diameter. Only downside is it's all plated these days so you will have to sandblast it to get it to take paint. The stuff is available in lengths at any home depot.