Well well
I will have to admit I thought the problem was much more than ignition related due to the backfire from hell, but turns out I was [mostly] wrong. I got a can of contact cleaner thanks to
@Slowbrick's suggestion and went to town on everything. Long story short, yes it fired up first go, but not without drama of course...
That would be the front muffler.
Thanks all for your help, and
@Raebird for your offer of a hand.
Dus anywun hav ae frhee mufla?