8.25 carrier wear

What brand of lunchbox locker are you looking at? It's been a while since I've studied on those, but I think your side clearance for the couplers is going to be out of spec. And then the whole business of the cross shaft holding the locker together... How egg shaped do you think those holes for the cross pin are. Honestly, I wouldn't even try to run a mini spool (if it were available) with that.