A kind of double glazing, the second time I deliberately decided not to use glass. The liquid glass that I used on Le Coureur turned milky white in places, either it reacted with the superglue or it had expired. So I resorted to the second product, but this turned out to be a bit rubbery and after a short time it looked unsightly. All the dust stuck and it couldn't be cleaned properly. I found a very interesting article in the French forum in which the "glass" was discussed, which at the time was made of very thin leather and treated with paraffin or something similar. It was rather light brownish and semi-transparent, so probably not real glass.I chose to make the window frame oversize for height and then beveled the top and bottom to fit the opening (by hand). My light divides were applied on top of a mica sheet to both the inner and outer faces (a sandwich approach) - to the extent it is noticeable, then, mine are perpendicular to the glass rather than parallel to the frame. For that aspect I like your method better.
But I'm not sure if there would have been wood divides on both the inside and outside faces in real life. I assumed so... but maybe not. I guess most everyone only applies the glass/mica/plastic on the inner face as you will be doing.