Odd sized radiators


I'm thinking of replacing some old (20+years) radiators but the sizes are proving a bit of a problem. I can easily find replacements for two of them, 600mm X 1400mm and 600mm X 1100mm single panel, but there's a also a single panel 600mm X 650mm and a double panel 600mm X 750mm. All the radiators I've found so far come in 100mm steps. Are there radiators that size out there somewhere or am I going to have to get under the floorboards and alter the plumbing?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I am not a plumber therefore the following is only my DIY understanding. As far as I know rads only come in 100mm length steps now. The alternative to altering the under-floor pipe(s) is to fit a slightly smaller size radiator and then make up the size difference with either a fixed length radiator extension, a telescopic rad valve extension, or a straight lock shield radiator valve.
http://www.heatandplumb.com/acatalog/40mm_Radiator_Extension.html http://www.heatandplumb.com/acatalog/copy_of_15mm_Straight_Lock_Shield_Radiator_Valves.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.