Anytime you build more than 4 to 6 identical turnouts, a fixture would be more cost effective than ANY RTR. Some RTR are simply prohibitive in cost effectiveness in any quantity. (Actually just handlaying is the most cost effective). Once you've built a number of turnouts, the techniques are easy to migrate with gauges to 'roll your own' using templates or just any proper geometry lay out.
The Railway Engineering link is included in the post above. (Base site:
http://www.railwayeng.com/ ) It's owned and run by a one man supplier, Stephen Hatch, he's been around for decades, advertises in NG&SLG often. Has and excellent handlaying tutorial on his web site. Supplies the two point "ROLLEE" gauges. Has some very fine hand throw target style points operating controls. He does subscribe to the strict MIN track gage and even a little narrower for reliability camp. There's no extra 'allowances' and you HAVE to have the wheel sets gauged correctly, otherwise the results are supperior operations, reliable, and in the "FINE' scale category. He's been the original source for 'make your own hand made spikes from spring steel wire' for over 15 years.
-ed-
_________________
-ed mccamey-
COSLAR RR -
http://www.coslar.us/NMRA Standards and Conformance Department
PROTO & FINE Scale Coordinator
I estimate I have about 5 pounds of coupler springs somewhere in the vicinity of my workbench.