Tomatoville® Gardening Forums - Giving new life to an offset smoker

I picked up a New Braunsfels offset on CL for $50, it's in good shape and was only used 3 times for steaks. Here's the beaut as I got it.
[img]https://image.ibb.co/hSQfKx/100_1844.jpg[/img]
[img]https://image.ibb.co/bvaEex/100_1842.jpg[/img]
[img]https://image.ibb.co/n7RbsH/100_1841.jpg[/img]

I took it home did a little cleaning and tested it for leaks using charcoal and chips, I found it has a few door leaks and it cooks hot especially next to the firebox. After researching mods I noticed the FB(fire box) was mounted higher than it need to be and the FB opening was too big. I decided to try to make it more like the Old Country brand offsets.

Here's a screenshot from Tom's Test Kitchen reviewing his Old Country Pit, you can see the size opening compared to this COS(cheap offset smoker).
[img]https://image.ibb.co/mkrZgc/Old_Country_Pit_fb_opening.jpg[/img]
[img]https://image.ibb.co/juaW4x/100_1851.jpg[/img]

First was to lower the FB and decrease the size of the FB exhaust into the CC(cooking chamber). I used plate steel and bolted it together in case this didn't work. I took it apart and started marking for the new FB outlet and pre drilled all the mounting bolts. I don't have anymore leaks between the FB and CC.
[img]https://image.ibb.co/kjkncH/100_1853.jpg[/img]
I got it mounted back up and you can see how much I closed off.
[img]https://image.ibb.co/nCq2XH/100_1877.jpg[/img]
[img]https://image.ibb.co/bVdd6c/100_1874.jpg[/img]
[img]https://image.ibb.co/hWyBRc/100_1878.jpg[/img]

Next I cut a heat deflector and made baffle/tuning plates
[img]https://image.ibb.co/fbRy6c/100_1873.jpg[/img]

I didn't like the FB door, it had leaks all around because they didn't install plate on the inside to get a good seal.
[img]https://image.ibb.co/cLJJjx/100_1858.jpg[/img]
[img]https://image.ibb.co/efTUrc/100_1857.jpg[/img]

I used the top of an old barrel and closed off most of the door, the vent still works fine.
[img]https://image.ibb.co/haGbsH/100_1875.jpg[/img]
[img]https://image.ibb.co/mi1LKx/100_1876.jpg[/img]

I ordered a new 4" stack to move it to the side at grate level but wanted to test it before doing that mod.
[img]https://image.ibb.co/dbMFWc/100_1855.jpg[/img]
I cleaned it up, sprayed it down with canola oil, set a water pan on the tuning plate filled with bacon chunks and water, cooked some pork fatty pieces and added a Sprite can to lower the stack to grill level. Let the seasoning/testing begin.
[img]https://image.ibb.co/mQ4UCH/100_1890.jpg[/img]
I let it go for about 6 hours and checked it every once in a while to add another log and check the temps. Here's some temps when the fire dropped, I'm impressed it's holding a steady temp across all the grates.
Left side near the FB
[img]https://image.ibb.co/bXd0Kx/100_1889.jpg[/img]
Right side near the stack
[img]https://image.ibb.co/mqCuex/100_1888.jpg[/img]
Factory gauge on the door
[img]https://image.ibb.co/jjeJ6c/100_1881.jpg[/img]

The seasoning worked great, it looks like it's ready to cook now.
[img]https://image.ibb.co/fz3NXH/100_1908.jpg[/img]

Later that day I fired it back up to smoke some stuffed turkey wings, it held temp perfect(about 250) using very little wood for this 5 hour cook.
[img]https://image.ibb.co/nQ7GsH/100_1913.jpg[/img]
A few hours later
[img]https://image.ibb.co/n8vKCH/0000639.jpg[/img]
It's blurry but it sitting at 250
[img]https://image.ibb.co/cWbRsH/0000575.jpg[/img]
[img]https://image.ibb.co/bKbbsH/100_1891.jpg[/img]
I cooked 2 hours then wrapped in foil with apple juice for another 2 hours, sticky juicy snacks.
[img]https://image.ibb.co/cKsGsH/100_1914.jpg[/img]
[img]https://image.ibb.co/mh7AKx/100_1915.jpg[/img]

The real test will come his weekend when I do a butt or brisket. I'll make a decision then about adding the 4" stack but I think I'll add it just to get that space on the grate and it should pull harder for better heat.

Any thoughts/ideas on the 4" stack? I did use a few pit building calculators and the FB exhaust opening and stack size is what I came up with.