Just purchased my '07 XK a month ago. It had a broken/cracked glove box door. After reading the many threads here about the problems with the tab for the lowering spring breaking off, I found mine to be just that. But apparently, the previous owner let the door slam open repeatedly and actually cracked it. I used a 'plastic welder' to bond it back together as shown below. Worked excellent. $25 on Amazon. The metal pieces sticking up are now cut off flush. Also, drilled a hole and inserted a 1/16" cotter pin to secure the lowering spring.

 

Here's the welder:

 

Great for the sun visors as well.

 

How about a picture of the finished job, when it's all cleaned up?

 

I think that other than the stakes being cut off, that is the finished appearance.
I would have tried super glue first.
WJ

 

I use my soldering gun with a paddle iron part to smooth and fix plastic. It works okay, but a good texture is hard to get.

 

I suppose it would be possible to sand the weld down smooth, add filler, sand, and maybe paint it. Since it is deep inside the glovebox and not visible, I decided to leave it 'as is'. I was seeing used gloveboxes for around $1800, so I'm satisfied with the result.

 

It doesn't jump out and say ouch, one needs to know it's there so...a visual compromise isn't too big a step considering the replacement cost of these 'plastic gold' assemblies.
I remember back in 1975 when MB got totally trashed by the transport companies because their door handles were falling apart, due to lower quality plastic. MB learned a lesson then, of course during that same period they went to a single row timing chain and had to replace them all several years later due to stretch and engine failures. Lessons learned the hard way!
wj