For the type 2, 3, and 3A Marlow gave the weight as "approx. 7cwt". That would be 350-360 Kilos in todays money.
I would allow a bit more than that, say 400 Kilos to be safe.
As you say, they break down relatively easily into 5 major pieces: Base, Column, Knee, Table, and Head (with motor).
For an example, I removed the table from one, it weighed 40 Kilos.