Is the pedal arm mounted all the way out on the crank arm spindle? a cottered crank usually has some amount of positioning variance because the cut for the cotter pin on the axle is wider than the pin itself. Bending the crank-arm will make it feel a little wonky, but not that bad for just getting it started, and you could always do a compound bend that regains pedal alignment. The forces required to bend the crankarm would be far greater than those applied while riding your ped and you would not have to worry about the steel returning to its previous shape.
I ran this setup and it cleared both my pedals and center stand though just barely with no bending of crankarms. Fully variated it did scrape my chain tensioner ever so slightly and I ended up removing the pedal chain and crankarms anyway. As for the exhaust mount itself I fabricated one, so I can't really help you with the adapter. sorry, no pictures though. good luck.