Speaking from a position of signifgant ignorance here but;

I had the engine seals on my '76 replaced. The mechanic did it in less than
1 hour, so I suspect he didn't remove the engine. (or he's really good!).
What he installed looks like 2 big mondo foam weather strippings. It is about
1" thick, and 2" wide by around 4' long. It has an fat H, or I cross section,
where the body, and engine tin fit into the two grooves.
It fit into a gap about 1" wide, and I assume that he just squeezed it into
place, and jiggled it until the 'flanges of foam' slipped over the engine, 
and body tin. Someone told me they had to be glued in, but there was no sign of 
glue where I rolled the edges up. It fits tight enough that I don't see any
need for glue. A big improvement over the ex-couch cushion foam rubber strips
the PO had glued over the gap between engine, and body, which were peeling off, 
and threatening to head for the fan;-0

Cheers
Bill Crick
'76 Type II/IV/VII