Yes. Sometimes it's not quite accurate, but that matters more on bigger models. You can look up the draft of a Z, do the scale math and double check, but unless its way off its ok to go with that.
To mount the model on a base, there's a number of ways. I'll just try to explain my preference.
For a really big ship like a battleship, some folks like to set it down on a row of crossways wood strips that sort of look like a drydock, although they don't. It gives the thing some gravity. otherwise the usual method is to place it on two or three pedestals. For a Z, two will be fine.
Decide where you'd like those to be. You'll want to pick locations more towards the front/aft center because that part of the bottom of the model will be flat and level.
I like to space them evenly in from bow and stern, say 1/4 of the way back and 1/4 of the way forward. Or a little tighter. Eyeball it.
Mark the centers of those locations on the bottom. Drill small holes. Be careful here because if the hull is in two halves, it might split.
Get a piece of 1x pine or whatever you have. Lay out those two holes on it on the centerline and drill holes larger than the screws or bolts you plan to use for mounting. Best to countersink them a little on the bottom.
Make sure the base is longer and wider than the ship. You can add an upturned end if you want, like I show but it's up to you. It does let you lay the model on it's side on the bench without busting stuff off.
Now you can either epoxy nuts into the hull at your two holes, or glue soft wood blocks over them. I prefer the blocks as nuts sometimes break loose when inconvenient.
Get wood screws long enough to go through the base, through the pedestals and into the hull enough to engage the blocks. Pilot drill the blocks.
Pedestals? There's all kinds of stuff available. There are nice solid ones, but I don't have a lathe and am not much at drilling and tapping holes. I prefer short pieces of tubing, actually a lamp part called a nipple. Fun to rummage through the stuff at the hardware store. If you find ones you like, get a number of sets.
Now you can mount the hull. I make sure it all works before I glue the deck on. After than there's no real going back. If you've already glued the deck on, there are ways to resolve that.