Questions about single seam trews.

[Huronbosun]

I’ve lost quite a lot of weight recently and my kilts are now all about 4-5” oversized and hang off me like barrels hung from suspenders.
I’ve got some very nice tartan and I’d like to turn it into a more traditional style of single seamed, high waisted, fish back trews.
Waist height and back style seem to be quite manageable, but the single seam stumps me a little.
My tartan has a repeat of approx 6”, so there’s a stripe at 6, 12, 18, 24” etc. In an ideal world I’d be able to lay out the legs so that a prominent stripe falls on both the front and back crease. But with a tapered leg, the two creases are 6” apart at the ankle and closer to 12” at the hip. I believe I”ll be limited to a stripe on the front crease, and a back stripe that runs diagonally out to the hip. I don’t see how it could work out any other way.
Am I right about this or am I off track?
If I’m right, and the back of the pants is going to show a big letter V, then I think it would be a reasonable choice to go instead with an outer seam.
The second question is about the front closure. A lot of the Edwardian style trousers I’ve looked at recently had a square flap and multiple button type fold down front. Is there any reason not to go with this style of front as opposed to a more modern zip or button fly?

[figheadair]

I cannot help with the construction but in terms of the seam, the 'traditional single seam' is a military practice dating from the late 19th century and was always done using double-width cloth.

In practice, this style is essentially the standard late 19th century military cut in tartan. By contrast, the oldest pair of tartan trews I have seen have a double seam, as do many modern civilian pairs.

[jhockin]

Regarding the multiple buttons flap front closure: decades ago I had a pair of surplus, heavy wool navy pants, that had such a front closure. When one has an urgent need, unbuttoning all those buttons can take, seemingly, forever. I often wondered if this was the origin of the sailors nor pipe dance.
😉