76' K-10 Stepside Need Some Help?

[wiggins]

Hey guys I am working on my new(to me) 76' K10 and as I fix stuff I want to make sure that it is factory correct so I am gathering info. Looking at the Id sticker I have afew ?'s

N41- Variable ratio power- this was an all time 4wd truck is that what this means?

71L -71 rosedale red soli- is this the exterior color?(trucks was repainted 5 yrs ago)
Zy1- solid color - I ask this bc the PO told me that the truck had white srtriping on it originally but he couldnt remeber what it looked like, was wondering if it was a factory sport

D73- PU box side rail- what did these look like

9G4- Stepside promotion- What does this mean(sport?) I ask bc it also list E62 as stepside box so what does promotional mean?

This is a Scottsdale 350/350 all time 4wd truck.

Any info appreciated. I will look all of this up if someone can direct me to the right place, thanks wiggins