Thanks for all the help and insight guys. I also moved house the same week so everything has been a bit chaotic, hence the late update.
Panic over. The lovely people at Lean (https://www.lean-business.co.uk/) sorted me out just in time as at that point the thread seemed to be pretty much in favour of replace>repair. Cannot recommend them enough, a really lovely couple.
Gig went really well and the cab sounded monstrous all night pushed to extremes by the weird and noisy bands on the bill. As an aside, the mad squat party was far better organised than the two mainstream clubs we played last week.
I'm going to attempt a fix on the damaged speaker, so will give it a go and update a little later down the line along with photos. I'm reasonably handy but not so with intricate/technical stuff, luckily it doesn't really matter if my patient doesn't pull through!