Congrats on the OA55. IMHO the OA series of motors are some of the best running and we’ll behaved outboards Johnson ever made. My OA55 was the first restoration I ever did in 2007 and it still runs like a top with no fussing around.
The muffler should be a nickel plated from the factory. The ends are either cast aluminum or nickel plated as well. I’ll have to look at mine to confirm.
