Handling 2 aiming points?

Yes. This is a well known conundrum with the 24's, Many alternatives out there, Mine alternative with one was ghost sights with point of aim on top of the 22lr dialed in center ring for the lower barrel. I did not have any windage issues with this rifle,
I like Cas's dual sight version, I Am in the process of mounting the dual sight system for a new to me but older 24 Camper with windage issues. Elevation is easy, But, Windage may be a chore.
Paul

Shotgun shooting lower than the rifle? Stack some dimes in the center of the barrel gap to bring them closer.

Shotgun shooring higher than the rifle? Put a pipe clamp around the center of the barrel gap to bring them closer.

Windage off? Twist the barrel band a little, if your gun has one.

I went the see thru scope mount route, though normally a shotgun is pointed versus aiming a rifle, I need sights for slugs. I have two sets of barrels for my 24V series D receiver, a 223/20 ga and a 357 Mag/20 ga (reamed to 357 Max). The 357/20 set was a rescue, when I received it there were no sights or extractor parts and the scope mount holes were tig-ed over. Also, my old eyes need all the help they can get with open sights and fiber optic bead sights help me.
On both barrel sets I mounted a Williams long front sight base, this required drilling and tapping a 2nd 6-48 blind hole in the barrel, a bit tricky on the 357 barrel due to the limited depth available compared to the 223 barrel.
For the rear sights of both I installed a Williams WGOS Small Sight base using a 6-48 Williams Shorty Ramp Dovetail Lock in the dovetail and then drilling and tapping another blind 6-48 hole for the Sight Base. Since the rear sight dovetail is so close to the scope mount rib the Williams WGOS Sight Base needs to be installed "backwards" with the ramp going "downhill" from front to back versus normally going "uphill". On both barrel sets I installed a Williams Fire Sight WGRS Ghost Ring Aperature for the rear and a Williams Fire Sight Rifle Bead in the front ramp.
On my 223/20 barrel set the front of the shotgun barrel floats in a ring attached under the rifle barrel. On the 357/20 set the front of the barrels are soldered together with a 1/2" long steel block. I prefer the floating arrangement as it reduces/eliminates bowing as one barrel heats up. I milled a barrel band out of a chuck of steel that slips over the barrels and drilled and tapped a 6-32 hole in each side to intercept the steel block between the barrels, with a drill bit I dimpled the block beneath the 6-32 holes. I then unsoldered the shotgun barrel from the steel block, slid my barrel band over the barrels, and secured it with a 6-32 setscrew lock-tited into each side.
One disadvantage is the rear sight screws that are facing up are difficult to access with a scope installed, so sighting in needs to be done with the scope off.
I noticed I referenced Williams stuff quite often. I am not associated with them in any way, it is just that their stuff is what I found to fit with what I was doing.
Now if I can just get my honey-do list whittled down so I can get more time to go shooting.

You did all this 35 or 40 years ago? You Gotta have a ton of knowledge to pass on, Would like to pick your brain sometime, I am an older guy (65) And have 4 24's.
I am allways tweaking both barrels with windage and elevation adjustments. I got them pretty much dialed in, BUT, These are combination rifles, Jack of all trades,
Paul

I have peep sight that goes on top of scope ....
They come with rings for scope ...
I do not like see thru mounts ..
Like scope to be as low as possible ..
I would say it could work for slugs...not sure ...
I am hoping my shotgun is not off and I can just use scope on 3 power for Gobblers ....