[Rachethead]

You said yours is a '53 model; from '52 thru '54, 336 receiver tops were not matted and are identical to those of the "55 and later Marlin receiver tops with the exception of the four factory D & T'd scope mount holes. I wouldn't D & T a "48-"51 waffle top receiver; but have no problems with D & T any smooth top 336 model; although I would take great care to D & T those scope mount holes EXACTLY in the same locations as a factory D & T job.
As your gun is a shooter, has no collector value whatsoever and never will; then by golly D & T the thing and enjoy shooting your scoped Marlin! After-market D & T jobs were at one time a money generator for the company, and the gun works after-market D $ T'd numbers of early 336s until the need to compete with other makers forced the company to provide those pre-drilled holes as standard equipment. Now that's my opinion; and if you want to have some idea of what you can expect after you D & T your Marlin, you can make that judgment by checking out my '53 model 336A below.

 

[Rachethead]

If you look closely at that rifle you will note that I performed a few aftermarket parts change-outs to include the trigger; I removed the original non-grooved trigger and replaced it with a trigger designed for the '57-82 pre-CBS Model 336 so that I could use an offset hammer spur. As I wanted a later model 336 appearance, I also replaced the original trigger with a gold-pated trigger, and added a late vintage sight hood and later vintage fold-down ramp type rear sight; no other metal parts have been altered or changed. There was no fitting to any of these parts; they simply dropped/tapped/slide into their proper alignments and the gun works slick and shoots straight.

 

[Rachethead]

Well JW, I posted a pic of a '53 model Marlin with a 2.5x8 Leupold VX-3; so you don't have to wonder how that would look. Fact is, it does look great; and best of all it shoots great with its old style Ballard rifling.
As far as maintaining originality, this is just one more example of the "purist" BS that is repeated over and over and over on this forum; not that I mind, but folks need to recognize BS for what BS is! So let us cut thru the BS and consider some actual real facts:
First of all, and again; unless your gun remains in AS NEW condition, the hard truth is that it has no collectibility. Maybe some sentimentality; but folks for pay extra for sentimentality; and and you have already stated this Marlin is a shooter grade.
Secondly, your gun is NOT a waffle top, so you're NOT even considering drilling a waffle top; although I'm no longer amazed that MO guys drag up the words "waffle top" EVERY time a D & T job is mentioned.
Thirdly, as your gun is a SMOOTH TOP receiver; a D & T job, if done to duplicate factory work, WILL NOT impact the shooter value of your gun. In fact, it might even enhance your gun's value. Why, because the overwhelming majority of people buying Marlin rifles want to scope them; if that weren't the case, Marlin rifles would not come from the factory D & T'd since 1956.
Fourthly, you may be a young cuss (all of us old timers were at one time, by the way); but regardless of how well you can see at your current age, even "hawkeyes" like ole Gunrunner can't effectively use peeps in near dark and thick brush situations (and age will eventually catch up with Brother Gunrunner too). A scope will extend your hunting hours and allow you to more accurately place shots and avoid wounded animals. And I can guarantee you this, if you listen to the purists and don't scope your gun when you really felt you should; then lose a chance (or worse, wound and don't recover) at a nice buck because you didn't have enough light to accurately use those peeps, you'll be laying awake at night kicking yourself for being so stupid!
Fifthly, it's your danged Marlin to do with as you please. Are you a man who knows what he wants; or are you the kind of individual who wants someone else to make his decisions?

Now, you asked for "opinions"; and you got a bunch to include my own personal unapologetic opinion. I don't care what folks think of that opinion, or what you ultimately decide to do; but I can tell you that my opinion is based on 45 years of actual hunting experience in the North Ga woods. Personally, I liked what Brother Hal had to say on this topic, "If I could get my hands on any old Marlins, I'd have every one of them drilled and tapped. Just because they didn't have suitable optics back then, why should you hinder yourself by not having a scope!" Short, direct and to the point; and absolutely on target!