Missing reed block gasket on 89 Mariner 150

I have been having running issues since I bought this boat in Sept. It had a bad miss at 1100 rpm and smoked a lot at idle. I checked compression and one cylinder was a little lower than the others- #1 I think it was. I did a link-n-sync and that helped a little but it still wasn't right. So today I got out of work early and decided to pull the carbs to check the reeds..long story a little shorter...the reed block for #1 looked odd, i could see a little piece of gasket sticking out so I pulled the reed plate and removed the reed block for #1 and the upper bolt was the wrong thread and the wrong length and thus never seated which left half the block loose and allowed half the gasket to break off and presumably get sucked into the motor. So..could that cause compression to be a little low on that cylinder? And should I tear into the motor further to find the misssing piece of gasket? Should I pull the piston?...not too hard to do at this point I think. Thanks.

Also, I was looking on Iboats at gaskets and they offer sierra or mallory...any preferences?? Or should I stick with the oem?