Greg,
Today I placed two 4x4 blocks (30" long) beneath the heavy end of the lathe, effectively taking most of the load off the casters on that end.
I was thinking of making up a steel platform instead of wood, but the wood blocks turned out to be very sturdy. I think they will suffice.
At the other end (the light end), I still have it supported on the casters. But I've noted that it's not very stable there, since the casters on that end are swivel-type. So I've got another wood block that I may stick under there.
I really need to get a machinist's level, but they are extremely expensive. I may make a first cut using a carpenters level and see where that gets me.
I won't really know what has to be done until I start cutting metal.
Ryan