to Bob, David
I'm not going to be much help with those Mercury gaskets and parts.
Most of what I have here are used parts for motors prior to 1960.
My main focus is on pre-1940 antique motors and parts.
If you go to my Website: www.penn.itgo.com
you can see a small sample of the kind of motors I deal with.
It would seem to me that those parts should be available here in the states in the aftermarket,or from Mercury Marine.
There is a supplier that has been recommended to me: www.fergusonpoolemarine.com
I have never deal with them.
They might be a possible source for your Mercury parts.
You can always try :www.marineengine.com , for aftermarket Sierra parts for those more modern motors.
Hope this helps.
Please add me to your forum as a source for the early engines.
I ship to Australia on a occasionally.
International shipping is not a problem.