Update: After a long spell of contemplating what to do with my .458 Mannicher Schoenauer regarding a scope fitting, with all the pro`s and cons of what scope base/rings will work, financial input to acquire a set of scope bases/rings which are out of my financial capability, and advice from members not ot scope a .458 Win Mag caliber.....I rejected the idea of fitting a scope on my .458 Mannlicher Schoenauer. I then worked on the next best option, to fit a functional ghost ring...

I went to Johan Greyling ( gunsmith/mentor) to take apart the .458 Mannlicher Schoenauer `s bolt apart and to examine the cocking piece sleeve. I noticed I have extremely few millimeters of metal to drill and tap without altering the cocking piece sleeve and maybe damage it.
Decision:
We decided the best option I have is to make an exact duplication of the cocking piece bolt sleeve mantel ( the en-longed shiny piece of metal usually metal checkered that rides on the cocking piece)

Notice the piece of metal between the bolt handle and safety. That is what house the safety pin...it is hollow and does not have metal to drill and tap. Dove-tailing the sides of this piece is also not viable.

The bolt only from the top:

This is where I want to attach/soft solder the ghost ring`s base onto.
Cocking piece sleeve from the side:

I have narrowed my search down to a ghost ring sight used on the Marlin type of rifles:

Here is another type of ghost ring I can look at:

I did converse with a person on another forum whom is extremely knowledgeable in building
miniature/scale Mannlicher Schoenauer rifles as a hobby , to get his input and ask him to design an aperture sight for me along these examples I uploaded .
Members , as always your input is more than welcome in this regards...keep in mind the telescope option is redundant...anything in regards to a ghost ring is more than welcome..I am sure you will agree that it is sound advice not to scope this rifle as some of your members had indicated previously...

I am of the opinion that the location of the ghost ring sight will favor my ability to see a better /improved sight picture, since it is near my eyes and a long distance between the ghost ring sight and the front sight/bead. I will remove the island v-express sight ...

As mentioned, this is my next best option...somewhere in the future with aging eye syndrome..I will need to fit a scope to see what I am shooting at...