Installing three piece gusset lining help

Hello,

I am deep in the throes of trying to make a traditional English Bridle briefcase. I want it to be a double 3 piece gusset with lining. I already have a side of 6oz bridle leather but I haven't ordered the lining yet. More on that in a sec. I am still trying to work on the logistics of the design on paper and with scrap leather.

My question... What is the best way to install the lining on the 3 piece gusset? Being that I want there to be a double gusset, I am running into a situation where I have 6 pieces of leather meeting in the middle of the bag where the two gussets come together (bridle, lining, bridle, lining, bridle, lining) and it is obviously very bulky. I have a simple mock up (using 3oz veg tan as a stand in for the lining) in the photos.

I did try to skive down the bridle leather on the flesh side fairly substantially (used both a french edger and a paring knife to help with consistency) but I am still left with a rather thick piece to sew through.

I really want to sew this bag using an awl and pricking irons. I am afraid my stitching is going to look like hell on that middle section where the two gussets come together though.

A couple of my thoughts....

**I could probably skive even more and then work out a way to skive the liner as well.

**Maybe I could buy some reverse pricking irons and punch both sides to try to stay consistent since it is a thicker piece of leather.

**I could try to pre punch the sections but I think that would only work if I used stitching chisels and I want to avoid that if possible.

**I could buy some of this double sided stitching nippers for the middle section and that would probably get me some straight lines. Again, I would like to avoid this option if possible.

Final question... would Alan Chevre Sully goat in 1.1mm (2.5 oz) be a good option for the lining? I have never worked with it before but seems nice and durable.

Thank you and sorry for the ultra specific long winded post!

-Sam