These levels look a lot like the older bases. Try to be creative, make your levels look different. I suggest focusing on the layout of the levels rather than decoration.
What i think could be changed/improved

• The floor design could be improved, its too messy in my opinion. Could be neater.
• Do not make tables that large, its unrealistic.
• The levels should not be as large as they are, lots of unneeded space. Your using up the entire room you have for a level. Try be focus on quality per smaller space. Your levels will appear less bland if done.
• A floor boarder should not wrap around the entire level.

You have potential, keep working on your levels. I suggest observing and taking note of levels you like around era.