G'day guys,
My brother just bought a 63 beetle with 1200 still in it that hasn't been started in 10 years, as was a barn find.

What would be plan of attack/parts to replace before trying to start it?

Cheers

If it turns over freely, fresh oil, battery, fuel as minimum.

Disconnect coil +ve lead, crank over until you develop oil pressure (if it cranks) IE: oil pressure light disappears.
Connect +ve lead, pump the accelerator and see if it comes to life.
Hard starting could be due to dry piston rings and thus not being able to develop compression until that oil splashes around. Putting a cap of oil in each pot will assist. In addition, Aa Can of 'start ya bastard' can help greatly too in low comp senario.

IF it doesn't turn over freely, pull off each cylinder head to ensure all bugs / crap / corrosion that has developed in the bores over time is cleared out (some exhaust valves could have been left open. Humidity and bugs do wonders getting in there). replace spark plugs. Depending how bad, corrosion in bores might need a fresh hone and rings.