Leaf Springs: 9 on Right/11 on Left?

[Theoriginalsilverado]

First of all, some quick background information about my truck:
1975 Chevrolet Silverado LWB
Camper Special
350 cubic inch motor
1 Owner Truck (my great grandfather)
20k miles

As I tell you what I noticed as I removed the bed yesterday, remember that the truck is a Camper special and was only ever used as a Camper.

Upon removing my bed, I began to look at my leaf springs. I knew that it was a 9 leaf set up, but I counted 11. I double checked both sides and the left side has 11 leafs and the right has 9.

I would simply ask my pop but unfortunately he passed away shortly after I was born. I was the only person other than him to take interest in the truck.

So, my question- Is this stock from the factory to account for the extra weight of the trailer on the left side(which is heavier on the left side)? Or is it a modification made by my pop?

By the way, he started a logging company and owned over 50 of these truck ks and if he wanted to he had all the resources to make this change.

I will upload pics tomorrow.
Thanks for your help