Box pipe internals

Having recently taken an angle grinder to a Vega exhaust, I thought I'd do the same with my beloved box pipe which had gone a bit rattly and noisy.
First of all, let me say I'm not posting this as a criticism of the exhaust. It's been up and down the country many times and all the way to Switzerland and back over the last 3 years.
The reason I keep getting it welded up is because I think it's boss for my engine and carb
The reason I'm posting these pictures is just to show a little insight into what's in these pipes.
This was 2014 and the first need for welding skills:

Ouch
These are today:


What has happened here is that the plate has fractured and was rattling around. Some folk would have consigned it to the bin by now (or stuck it on ebay!), not me, I like a challenge. Pity I can't weld though.
First of all, let me say I'm not posting this as a criticism of the exhaust. It's been up and down the country many times and all the way to Switzerland and back over the last 3 years.
The reason I keep getting it welded up is because I think it's boss for my engine and carb

This was 2014 and the first need for welding skills:
Ouch

These are today:


What has happened here is that the plate has fractured and was rattling around. Some folk would have consigned it to the bin by now (or stuck it on ebay!), not me, I like a challenge. Pity I can't weld though.