How do I fetch the first version of an asset?

I have searched the internet for two hold days and I cannot find an answer for this: how do I fetch the first version of an asset.

Let’s say I had a package published which was a mesh in the shape of the letter A. But then, later I updated it to be in the shape of B. I want to let people fetch the first version (with the A) even if the latest one is something different.

There just doesn’t seem to be any API for this.

So basically (a rewording of my question): How do I fetch the first assetversionid of an assetid?