Mike's reference to capacitors goes for just about any old tube (valve) radio. They usually are the weakest link if the radio has been sitting for a long time.
Definitely clean and re-lube the bearings on the dynamotor. There has been some discussion on one of the 19 set groups about not running the power supply without a load. Most REMEs and rad techs would apply a low voltage and gradually increase it to "form" the capacitors. This allows the chemicals inside to slowly become "normal". If you can't do that, as a sapper with EOD experience you should have no problem
I've seen photos of a catastrophic failure of C42, the receiver power supply filter cap. It looked like a destruct charge went off.
I've just finished a MKII and power supply for Mac's WC and didn't have to do any repairs to the radio itself. In fact most of the units have been very reliable after 65 years.