I'm in the process now of making two custom-sized 6-over-6 windows to
replace a couple of damaged windows in my c. 1830s colonial. Although
construction of these old windows is fairly simple (i.e flat sides in the
stiles that run in flat runners in the window case), I was quoted about
$500-$600 per window to have them built. I nearly choked at the quote and
figured I could do this. Windows are a first for me and I'm looking forward
to the challenge. After all, I did build a new exterior door with pegged
mortise & tenons and 6 raised panels that I (and more importantly, my wife)
was quite pleased with.

I bought the Whiteside window sash bit #6050. Also bought a a 13' long
board of 6/4 x 6" quarter-sawn western red cedar for about $56. Should be
plenty of wood for both windows and allowing plenty extra for mistakes.

Have already planed down & cut some scrap pine to size and after about an
hour of trial & error adjusting, I have perfect fitting copes on the rails
to match the stile pattern. They are now my set-up jigs. Mullions are
next.

Off to the workshop now to finish the test window.

Joe T