What is the original application of this tire cover?

[ASA]

I bought this spare tire cover a while back with the intention of repurposing it.  However, since it appears to be in very good shape, I felt obligated to figure out what it came from before I may do anything with it.  The guy I got it from purchased it for a v12 Packard(I think).  But, he said it was not correct for his car.  There are measurements in the last 2 pics.

 

So, can anybody tell me what this is originally from?

 

Thanks in advance for any help.