Elizabeth:
The Marshall JVM410H is, indeed, a tube amp. Since it's a new one, you can probably get away with shipping without removing the tubes, but if you can get to them easily enough (on some amps you can just reach in the back, others you may have to remove a panel first), it makes sense to just pull them out, wrap in bubble wrap, and pack in a small box to be included in the big amp shipping box. The consignment idea may be the best way to go.
Bill, tgo