When i was tractor shopping i decided on a
L3800 and i noticed mine had the stickers over the holes too I remember thinking how cheesy it looked.
When i took delivery it had the handle added to the right side and they never said a word about it nor did they charge me anything for it.
I guess i just got lucky and they accidentally put one on.
I will tell you i use it all the time too it is very handy to brace yourself on rough ground or to hold onto when looking back.
You'll be glad you have it once you start using it.As far as the nuts go Id go stainless anyway if i were installing it myself.
I just ordered brake hardware and hoses/lines for my dodge truck and i had to look at the parts diagram and order every little part, nut,and bolt separately to get a complete assembly.Surprisingly it was still cheaper than the complete aftermarket assembly big companys dont seem to look at those little things through the customers eyes.
Imo it should come with one on there from the factory those stickers are a joke and that handle probably only cost them $5.00 to create.