John,
a hollow wooden mast with 20% wall thickness will have 13% lower breaking strength than a solid mast of the same outer diameter. However, the hollow mast will be 36% lighter, and since much of the stress in a sailboat’s mast comes from rocking and rolling, rather than from wind pressure, I would not be surprised if the hollow mast (of same diameter) will stand up just as well as the solid one. Moreover, by increasing the hollow mast’s diameter with only 4.7% over the solid one, the breaking strength of the two will be the same.
This will raise the weight of the hollow mast to 1.0472 = 1.097 times the slimmer version. The beefed-up hollow mast will thus be about 10% heavier than before, but it will still be 30% lighter than the solid wooden mast.
As for boom, I agree with David. Only on my last (5th) junkrig have I beefed up the boom a little. This has let me move the tackline (TL) aft so it looks like a kicking strap. That lets me hoist the full sail until the TL is taut, and this ensures that the leech of the lowest panel will not flutter in a rising breeze. The boom’s dimension is now the same as the upper sheeted batten.
Good luck!
Arne
PS: Only on my first boat, the Albin Viggen, Malena did I sail first with a solid pole mast and then with a hollow one (25% lighter). There was no doubt that the boat stood better up to rising winds with the lighter mast. However, your Rawson 30 is much heavier, so even a solid mast will feel much lighter on that boat. Try to compare the mast weight with the displacement of the boat. If the ratio is not much over 3.0%, you will be fine.