Is my take on this early chrono accurate?

[woolshire]

I’ve owned this watch for 20 years. I believe the dial and hands are in amazing condition, showing just enough patina to make me believe they could be original.
The case is stainless front and back. The center of case appears to be maybe not stainless (base metal?) and it does have a serial number on the back, but no ref number. I have always assumed the watch had a gold case but it was likely scrapped and this case became the replacement. The movement looks original to me, although someone got some engraving in on the balance cock and inside the case back.
I love the watch as one to wear. I bought it as somewhat of a put together watch, so not buried in it.

What are the vintage experts take on this one? Thanks!