the interior

[Ashiuhto]

Is the following sentence acceptable?
The interior of the train station, with superb, luxurious, and exquisite decorations, was having a nostalgic design and inspiration.

[Raymott]

Is the following sentence acceptable?
The interior of the train station, with superb, luxurious, and exquisite decorations, was having a nostalgic design and inspiration.

No, you can't use "was having" like that.

[Ashiuhto]

The interior of the train station, with superb, luxurious, and exquisite decorations, had a nostalgic design and inspiration.

[Tdol]

With its superb works better for me, but the sentence is a bit flowery for my taste.

[5jj]

... the sentence is a bit flowery ...

.. or aureate, eupheuistic, grandiloquent, magniloquent, ...

[JarekSteliga]

The interior of the train station, with superb, luxurious, and exquisite decorations, had a nostalgic design and inspiration.

NOT A TEACHER

In my opinion things don't have an inspiration but rather either are an inspiration or simply inspire.

Therefore I would rewrite your sentence thus:

The interior of the train station, with its superb, luxurious and exquisite decorations, had a nostalgic design and was an inspiration.

or

The interior of the train station, with its superb, luxurious and exquisite decorations, had a nostalgic design and inspired.

It is people who can have an inspiration, meaning that a wonderful idea has dawned on them.

BTW is "inspiration" really a countable noun?

[Barb_D]

She is an inspiration to her classmates. Yes.

I was guessing that the designer was inspired by something.