[David Simpson]

As discussed in Roger's adjacent thread posts, and others - These 1950's/60's marine band sets had rudimentary antenna matching/tuning. A length of wire between the masts, then down through an insulator on the wheelhouse roof to the Tx. Excellent "earthing" to the metal hull or to seacocks & engineroom metalwork in wooden boats.
With the restored sets I've had, by trial & error I discovered that an 80m Doublet with a ladder feeder was best. However, ground conditions are a problem for earthing. In the 21st century, with houses full of expensive domestic electronics, I would avoid using the utilities' "electrical earth". I ended up digging narrow channels into a grass lawn & burying a "radial" of 16mm sq bare copper wire, plus a couple of rods. All line-tapped together, then fed back into my workshop with 16mm sq insulated copper wire. A Johnson Matchbox supplements the Tx's basic variometer.
Before entering the 80m AM amateur world of interference, personalised nets, and SSB yappers - check your rig's capabilities using WebSDR. Some amateur folk look down on restored ex marine rigs, and may sometimes infer that you're off-tune or drifting, compared to their 21st century expensive rigs. This can be disproved by using WebSDR, and therefore put your mind at rest.

Regards, David