Hollywood (and video games) demand intimidating presence, over functionality…
Maybe I should screw a foot long supp on, and attach an even bigger scope, to that…!!
To, you know, keep it within the theme….!!
And then make a Jill sandwich…
NOW its proper Holly-wooded…!!
“Escape from New Holster.!!” … mission impossible.!!
introducing the hero…“scope-scope Supp-Supp !!”
Enough to give Barry an inferiority complex…!!
Ok…EFNY pistol sorted and adjusted…
Moved the rail forwards, to sit in the correct position.
End of scope, just short of barrel.
Internet reference pic…
The blaster has a dovetail slot, and a M3 screw, for the rear sight.
The M3 hole could have been used for retention…but its too far rear, with the rail moved forward.
The rail is now held, by the front grubscrew only…done up nice and tight.
Not ideal, but ok…
No extra drilling reqd.
Final result…
Rear of mount is hanging in space…but still quite tight…just don’t pull on it…
About as close as a replica as your gonna get…
Along with big brother…
You just got Plisskin-ed…!!
Nice replicas, both of them. Time to think about how your going to display them, Beemer. 
Are you thinking about a way to tie-in them into the movie? Maybe mount them up in front of an EFNY cinematic poster or something similar? Maybe a framed copy of the DVD sleeve… 
Then they’d be a real feature. 
Otherwise anyone not familiar with the franchise would just assume they’re a couple of very weird-arse guns owned by someone with a distance vision problem.
Ah, ya gotta love Hollywood. 
Mr Mcgoo has no problems,
Having vision problems, and guns…
Murica…!!
But yeah… a blown up and framed wall poster could be the go…