bkahler

If you're drilling into brass I believe you are drilling into the lock itself.  If you look at the pictures below, you'll see the lock has brass in it.  I do not believe there is any brass in the rest of the framework or the screw that retains the lock.  In the below you can see a little round nub sticking out the side of the lock retainer cylinder.  That nub is threaded inside and that's what the screw is inserted through to retain the lock. 
 
By the way, this is for a B3B, which I assume would be the same as your B1B.
 

 
 
Here's a better view of the brass portion of the lock.  The screw presses into the V notch in the lock.  I think you  need to stop drilling and move up to the next sized drill bit to drill out more of the screw.  That is of course, you started with a small drill bit first.
 

If you're drilling into brass I believe you are drilling into the lock itself.  If you look at the pictures below, you'll see the lock has brass in it.  I do not believe there is any brass in the rest of the framework or the screw that retains the lock.  In the below you can see a little round nub sticking out the side of the lock retainer cylinder.  That nub is threaded inside and that's what the screw is inserted through to retain the lock. 
 
By the way, this is for a B3B, which I assume would be the same as your B1B.
 

 
 
Here's a better view of the brass portion of the lock.  The screw presses into the V notch in the lock.  I think you  need to stop drilling and move up to the next sized drill bit to drill out more of the screw.  That is of course, you started with a small drill bit first.
 

My stock 16" wheels fit the Rusty Hope front conversion just fine.  I'm not sure Rusty Hope is still selling conversion kits.  Last I heard he was not making new kits anymore, just selling off the rest of his stock.  If he does have a kit available I would suggest you jump on it before they are all gone.
 
As for the rear, with the 1.5" spacers the stock wheels fit just fine on a Cherokee diff.  I don't remember the exact number but the Cherokee diff is at least 3" narrower so it would probably look rather funny with the wheels tucked in so close to the frame. 

I installed a PCV system on my 51 218.  I used a Fram FV333 PCV bought on ebay.
 
Here's a link to my PCV installation,
 
 

My 51 B3B-108 tail gate is 49-1/2" wide across the top rectangular section.