Re: Transom plate gasket
The "blubber hose" is in the connecting components section and is called a sealing strip. If you set it in the groove and it still sits above the edge then don't know why you wouldn't want to re use it. Use your common sense and check for cuts, cracks, divots, flexibility, etc. to determine if it's still useable. A new one will run you around $70.
Absolutely replace the o-rings for the 6 perimeter bolts.