Back in the days of old Redfield,there were not so many choices.For most folks "scope" on a hunting rifle meant a steel tube K-4 Weaver.Optics have evolved,but that was a reasonably priced,rugged servicable scope.
Most everybody I knew was happy with 4x.
While Weaver was the standard,Redfield was the step up .It was the classy scope to have.They also pioneered Accu-Range,using stadia for range estimation.Leatherwood took it another step with the ballistic cam mount,plus the custom reticle.
Redfield made pretty scopes,nicely finished,that looked good on a fine rifle.
Back to the OP's question on power,note the ART scope was used at modest powers,and functioned at about 1 x per 100 meters.
Lets not forget some pretty fine shooting gets done with iron sights.
And,for the OP,study up on exit pupil,objective sizes,etc before you buy.
Nutshell,your eye pupil varies with light.Approx 7 mm in darkness,5mm low light,down to 2,maybe 2.5 in bright light.If the exit pupil of your scope is smaller than your eye pupil in the given light,image quality degrades.
Divide power into objective lense for exit pupil size.My 6x by 42 mm Leupold has a 7mm exit pupil and gives excellent low light performance,better that the naked eye.
A 10x by 42 mm scope will work well during daylight hunting hours,but will begin to degrade dawn/dusk,maybe.It will have a 4.2 mm exit pupil.
A 24 x scope with a 50 mm objective will have approx a 2 mm exit pupil,adequate for good light,but it will be darker than the naked eye in any marginal light condition.
Big objective lenses are required to get good performance out of high magnification.Big lenses of quality cost a lot.Glass is heavy.Obne of the more imortant problemd is large objectives require tall rings,high mounting.This can cause you to have to hold your head up off the stock to see.
IMO,larger than you need to get the job done is a liability.
On the modern Leatherwood question,old Redfield is gone.They made the scopes in Denver.There is a new Leupold Redfield,but neither have anything to do with the Leatherwood name.
Leatherwood has a line of scopes.I do not know them,I have stayed away.I have heard their Malcom type repro antique scopes seve well,though the mounts are somewhat crude.I think the repro 1903-A4 snper scope offered by Gibbs/OWS is a Leatherwood.It may be that for the $300+ Leatherwood can build a repro,low tech scope of decent quality to suit these rifle,built to spec.
I have no experience with the Leatherwood.
In today's scopes,a lot has evolved.An example is the Leupold CDS system.It is 15 MOA of short,target grade turret with a custom graduated knob to your specs.Its not horribly expensive.The higher end European scopes offer sophisticated turrets.Kenton industries makes custom target knobs to your ballistics,and there are Christmas tree reticles,etc.
There are other choices besides the ART mount