OK....
I like it. Very nice!
Since you asked for a critique, here's what I see....
First potential function problems,
Please post a close-up of the tang and breech behind the barrel breechface....where the back of the barrel and tang area meets the breech face of the stock.
It looks like you have a little gap between the breech face of the stock and the rear face of the barrel.
If so, this really needs to be fixed as recoil will place all force on the rear of the tang, tag bolt and the rear lock bolt. All those points can crack the stock at those places and cause a wandering zero as far as accuracy. We need a close up because sometimes photos are deceiving and that might be where the brown did not take. To me right now it looks like a gap.
It looks less than a 16th so you might can ease the barrel assembly back or glue in some wood ..Like I said a more detailed photo will help us to offer a solution if there is a gap there.
It's really No Biggie, Wallace Gussler one of the great current builders has said he would like to build one rifle in his life that did not have glue!
Pins...
If you have slack around the pins, this is even more reason to fix that possible gap behind the barrel face. Now the holes around the pins can be fixed. In my opinion...just re do them. Take some maple, shape these little pieces like you are making a tooth pick and fill the hole. Do each side.
Once the stock is repaired, the underlugs will need attention. Your best bet may be to replace the underlugs. You might can slot then or even remove them and peen the old pin hole closed in a vise. What you do not want is your old hole in the lug to grab and break that 16th drill.
I recommend new lugs.
Use a depth gauge to lay out the target on each side of the stock. You will drill half way from each side. With practice and good layout both holes should meet. Drill the,pin holes first with barrel out. Replace the barrel, Then drill through the lug. Do not go all the way though the stock. Go through the lug, stop ,and drill through the other side.
You can practice drilling on a 2x4 with the targets laid out on each side. With practice you,will meet the same hole.
Little non functional details...
Once again I really like your Rifle!
It can go slimmer. From above looking down the widest part of the lower forestock ahaead of the lock panels should be about 1/8 inch wider than the barrel. This is the fattest part....about 3/4 up from the bottom of the stock. On the upper forestock, the stock is 1/16th wider than the barrel at the fattest or widest part of the stock with the transition at the entry pipe.
A small detail but something to consider if you re do the lugs and pin holes.
Lock Bolts....
I like the clean look with no side plate. In my opinion, round headed bolts look better without a side plate where the square head bolts look better with a side plate. So personally, I would round off the heads of those Lock nails/bolts.
Immediately behind the barrel....you can bring the wood down mimicking the octagonal flat.....this is a small deatail. This brings the top edge of the panel closer to the top of the lock and closer to the rear lock bolt. Like I said a small detail that you might incorporate in your nest one.
Look Here....
http://americanlongrifles.org/forum/index.php?topic=8015.0 Note how slim the rifle is when viewed from above. Where you can read MG on the barrel.
As said I really like your rifle. The only thing I see that really needs attention is the possible gap behind the barrel. All else is detail stuff.
PS....I have to repair a pin hole on one of mine.