Question about broken downstem (xpost from r/pieces)

**How it broke**

The top of my downstem got broken at a party, and after several more months of use, there was no more remaining exposed downstem due to shitty glass. My slide got caught on a piece of the chipped glass, and it snapped in two on the inside, making it unusable

**Measurements**

The insertion point where the downstem would be is 14 mm.

The slide is 8 mm

The old downstem is 12 mm, but that is at the base (the part that was inside my bong), but it also seems a bit warped. As I said before, the top broke at a party so im not sure how wide the opening where the slide goes originally was

**My question**

My bong is just a straight simple tube, and as you can see in the picture, it is not glass on glass. Can i purchase a 14mm/14mm downstem with a diffuser and just insert it into the grommet and have everything work out? Or do i need to find some other alternative? Any help is appreciated, thanks in advance.

Sorry for shitty ipod pictures, if anyone wants to see any other picture just ask but i think i covered the basics. http://imgur.com/a/qbEm8

Edit: Just tried to put the remaining broken part of my downstem back in the grommit and back in the hole but I could not. It was too difficult/tight. Not a good sign im guessing