[Closed] Second hand shed - treat and paint?

Where better to get shed advice than STW!

I have bought a shed second hand. It's in good condition (no rot), but has seen several years of weather without a paint/protection top up, so the shiplap is dry and grey.

As it is going to be erected (fnar) in a tight spot, I'd like to treat it before it goes up.

Has anyone any suggestions on what to treat it with for maximum protection? It looks as though the "Shed" products from the likes of cuprinol and ronseal are for rough sawn timber only so I'm not sure they're suitable.

Wood preserver -> primer -> undercoat -> gloss? Ideally in as few a applications as possible, as it is a 12x10 shed so has a lot of surface area.

Thanks

PS: This is my first login since the great hack debacle. That's a long time lurking! 8)