I'm not a monitor expert -- I'd wait until someone else chimes in. That said:
- The assemblies aren't identical, as I'm sure you know. You can't just put a slant top assembly into an upright machine, obviously.
- The chassis are likely the same, but I'm not 100% sure on that.
- If you're familiar with and comfortable with CRT discharging procedures, yes, you should be able to swap the tubes. If you have not discharged a CRT monitor before, this is probably not the time to start without having someone experienced to show you the proper and safe way to discharge a CRT monitor. CRT monitors (well, the capacitors on the chassis which connect to the monitor) can carry a potentially deadly amount of voltage, even when unplugged from the machine. If you are not familiar with discharging a monitor, do not attempt to perform any work on the monitor until you learn how to safely handle it.