The plan is to make the new window a bit smaller, since the original window have been partly covered by adding 3 rows of bricks. I assume that it was done because the machinery stable was once used to house pigs. And if they were able to get to the bottom of a wooden window - they would eat it. Therefore all the windows on the backside have been made smaller by adding three rows of bricks.
I intend to add another 3 rows on the outside once the window is going to be installed, so it will look nice.
There is no need to make a window that can be opened, so it will be a fairly simple model. The original frame is made using 1 3/4" thick stock. I am going to use some rough 2x4" stock, so my frame will end up being close to the original but maybe a tad stronger.
I am going to make the arch on the top part in the frame itself rather than nailing on a small ornamental arch. I expect that it will look OK.
At first the stock was cleaned up using the jointer, and then I sawed the pieces to the correct length. except for the dividers.
I then planed all the rabbets. I think it would have been faster to make the rabbets on the table saw, but they wouldn't have looked as good.
The idea is to dovetail the frame together, and mortise the dividers into place. But that will have to wait for another day.
The finished gable and the disassembled scaffolding.
The window (or what's left of it).
Truing up the stock for the frame.
A bunch of curly shavings from the rabbet plane.