I have owned this first year production Remington Autoloading Rifle in the 1400 serial number range since 2013:
Do all model 8's and Autoloaders have a rivet holding on the front sight? Also, the rear sight on mine appears to have a slot where you would be able to slide in an insert and a set screw hole for it to be held in place. Was this feature not included in the later runs of production? Can I find original or reproduction peep hole inserts for the rear sight anywhere today?
For what it's worth, I was at the original Remington factory in Ilion, NY last year and they have a museum featuring a lot of the guns and their prototypes. The "tool room" prototype and "pattern gun" models they had on display had much higher serial numbers than mine and seemed to lack many of the earliest features (safety lever nub, hand scripted caliber markings on barrel shank).
The front sight was basically stolen from me by an unscrupulous gunsmith years ago when I went to him to fix the front sight being loose and he completely replaced it without consulting me and did not return the original to me. I asked him several times to return it and he just stalled saying he couldn't find it and he wasn't sure it he kept it.
Right now the 2nd replacement front sight since then has come loose yet again and I would really like to come up with the best solution. Here is a picture of what I'm working with:

I also really want to know whats up with the slot and set screw hole in the rear sight (potentially for an insert?)

Also, on the left side of the receiver, there are three tapped screw holes presumably for some kind of side mounted scope or peep sight mount. The three holes form a constellation around the pin for the pivoting safety lever on the other side. From what I can tell this was for some kind of lyman rear peep sight? Where can I get one of those (seeing as I've already got the holes to mount one)?

This picture from the website seems to correspond to the holes on my own firearm:
Thanks for your consideration.