Plastic can be welded
I got a fuel tank done not so long ago for the mower however if they crack it often means the whole thing is brittle and although you might be able to fix it now it might fail rite next to it later.
Best bet would be to hit eBay or I think one of OBT site sponsors is a Honda rep they might be able to point you in the rite direction.
Or someone on here might have one
Good luck buddy it looks like its worth spending a dollar or two on it