(Updated 28th Aug 2016)
My new coachroof rails have been cut by Fine’s Lumber – I drove to Austin and collected them, and must now fettle and fit them.
The old ones have some inch and a half of curvature at the mid point. 
The profile of the original is asymmetric, more rounded on top than the bottom, whereas my new ones are symmetric. I will round off the top edges.
The new ones are also undrilled, so I have to get the holes lined up correctly. As Frank is 3 hours drive away, I do not want to be shuttling back and forth, and am not sure whether to drill and measure at the boat or at home, using the old rails as patterns.

Then I shall need to decide how to treat the new teak – oil, varnish,

Update.
I have measured up the new rails to drill the holes, and will do the drilling at Frank
The difference in the profile:

The end of the old rail, on the left, is sloped out from top to bottom, and I have allowed one inch on the new rail, for cutting errors. I will match the emd slope, but probably not the profile, which is wider on top than on the bottom.
The holes seem to be offset from the centre line. This is most apparent when viewed from the underside of the old rail. The rail curves inboard,naturally amd the holes are biased to the inside of the curve:


A pencil fits in the holes just enough to centre the pencil mark for the hole, assuming that I have it in the right position! That is why we use pencil. Measure twice, cut once, they say, although I tend to measure several times and still get it wrong. 😉




