The first 40FP's came with a number 843 muffler which had no baffle. Later versions came with the E3030 (I think?) muffler which has a baffle. The early 32F's first came with the baffless #843 and were later changed over to the E3030 with baffle which is what the 32SX comes with.

I wonder why the previous owner painted the engine and muffler as that would have a tendency to retain heat - not a good idea.