It's good to see some other people working in their basements with basic tools and makeshift workbenches.

Although I'm in the garage now...it's so cold...
I just finished the building part of my table tuba last weekend:

And at this point I'm just trying to fill all the screw holes and sand it smooth. I still have no idea how I'm going to finish it yet though...
It's a fun (and frustrating) process. I would agree though, if it's off by a 1/16th it's not that big of a deal, just make sure there is glue filling the gap and it will seal itself shut. Some advice having just finished it, try to get stuff square from the get go. I'm on my second BFM sub and I still haven't done it quite right either time so when I lay my TT down on a cement floor it wobbles a bit.

grrr
Actually, I used most of my two 4X8 sheets for my 17'' wide TT. I've got a long strip about 18'' wide left over, and a square piece about 2', but that's about it.
Another good tip is to double and triple check to make sure you drew the lines in the right places, and remember to glue your boards down the correct sides of the line...that is not a fun mistake to make...
Have fun!