doublet flap connection?

[madmacs]

I'm thinking i have to make a piece on the inside for the flaps to sewn on to... Right?

This would then largely be covered by the lining...

Anyone have pics/info? Even one of the inside of the doublet showing the lining would likely be helpful

[fluter]

Madmacs, I think your idea is correct.

I'm thinking it would be handled like a pocket, with some interfacing or something to anchor it. Especially so, if it is a pocket, too.

Your public library might have some helpful books on tailoring. There is one by Creative Publishing called Tailoring: the classic guide (something), which shows hand/machine and fusible/sewn-in options. I have not put it to the test, but I found it a good introduction.