Saving Old Seagulls

The piston has moved!
But it is very stiff to turn over the engine with a spanner.
Took the head off, the bore seems fine.
I'm wondering if the stiffness is the main bearing or something like that??

I've just had a look at the old plug, it's hot a funny ground electrode that doesn't sit over the centre electrode but it sits to one side!

Just squirted even more WD down there before bed, I think this will be a nightly ritual this week!

It's certainly complete, although there seems to be a few bodged repairs/modifications of the clamp etc.
Yes, lots of WD will going down the plug 'ole.
Will a hot air gun be OK to warm it up??
I removed the old Champion 8 COM plug.
What should I replace it with??

Here are some photos..

Hi, last night I bought a 25hp Blue band Merc and had a Seagull thrown in to the deal for free. I'm more excited about the Seagull than the Mercury! The number on it SJP1415E6 indicates that it's a May 1966 Forty Plus model. It's seized, whether that is through standing or failure I'm not sure. The ...