Sheaffer TM Touchdown Barrel Crack Fix

[LoveBigPensAndCannotLie]

More Sheaffers, more problems. As I posted in the impulsive pen buy thread, I recently got one of the Sheaffer TM "Triumph" pens (the all gold-fill body ones). The threads have a not insignificant crack in them:

 

 

 

 

To my eyes, it looks like it was subject to a previous repair that did not hold up, the crack was a little grody when I got it, looked like there was some kind of sealant or shellac applied to it.  The crack extends on the inside the entire length of the threads, more or less. Note that it is cracked under the metal ring at the end as well.

 

I did a few things to try to fix it that might make you all cringe. I first tried using a tiny bit of super glue (emphasis on tiny, I dipped the tip of a toothpick into a small drop of it and used that and capillary action to spread it along the crack) to try to at least provide a seal. This did largely nothing, it would not retain air pressure for a proper fill.

 

Second thing I tried, I slathered the crack in shellac. I understand this would not work without the overlay but I figure I just need it to provide a seal between the crack and the metal overlay where air can escape. This plus a healthy coating of silicone grease on the threads seemed to have worked. I waited about half an hour to screw it on after applying the shellac, so hopefully it does not bind too much and I am able to unscrew it in the future.

 

The pen fills somewhat well but I know this is not a permanent fix, likely it will open up again, especially in the exposed area outside of the overlay. So... is there a more permanent fix? Did I ruin the pen for good with my "fix?" I really like this pen and I am assuming finding a replacement barrel will not be easy. I read that while these are not rare or "valuable," they are more uncommon than the Snorkel variant because they were made for a much smaller duration.

[FarmBoy]

You remove the barrel liner and replace it. 
 

you can make one from a crappy black pen with a name on the barrel. 

[LoveBigPensAndCannotLie]

I figured this was probably the best solution... how difficult is to remove the liner? I am assuming some heat is needed and it'll come out. The blindcap came out by itself when I unscrewed it, needed to shellac it back into the overlay.

 

Is the inner plastic literally just a normal TM pen barrel or is it a thinner barrel specially used for these gold overlay pens? I don't have any spare barrels but I will keep an eye out.

[FarmBoy]

Special. Thinner. 

[es9]

If it’s already broken, I personally wouldn’t feel shy about using a decent amount of heat. It’s not like you’re trying to save the liner. Worst case scenario it starts to deform and comes out really easily. 

[LoveBigPensAndCannotLie]

Hmm, I guess that's true. I think the biggest thing is finding a replacement inner barrel, not sure how to go about that.

[es9]

Per @FarmBoy, why not just find a cruddy black snorkel barrel and turn (or I suppose sand if you don’t have access to a lathe) it down to the right size? I imagine it’s just shellacked in place.