http://www.cbtricks.com/Amp/maco/maco_300b/graphics/maco_300b_sch.pdf
looks like two 6lb6's in the driver stage and five 8950's in the final stage.
The 8950's are worth more than the amplifier is.
I used to own that exact model I haven't heard or seen one since mine in the 1980"s. Never had any tubes go bad only the transformer and I replaced it right away. When mine was tuned and on high it really did dim the lights and just about anything that had a speaker or could reverberate you could hear me on and a letter from the FCC let me know just how far away I could be heard over a T.V. telephone, and home and car radio's.
Unfortunately a full set of replacement tubes will far exceed the replacement cost of the entire amplifier. If it was insured, claim the full value and let the post office buy the paperweight they created.
Any amp or heavy Radio should be double boxed with 2-3 inches of good packing between the boxes and the tubes removed and shipped separately. I have no love for people who are clueless about shipping radio equipment. Take good pictures and file a PayPal claim.
It depends.
How did you purchase? Ebay? Gift payment?
We needs the details.
you should contact the seller and demand a refund .he should have insured it for the full amount .and he should have packaged it better .
as long as you did not gift the money thru paypal they can help you .
file a dispute .received damaged non working item ,you have a case .