I wouldn't sweat the little chatter marks on top of the receiver and I'd just tighten up the screw.
I know you're interested in putting a scout scope on it, and it would be a perfect platform for that application, provided you weigh the pros and cons of the setup and decide it is right for you. It is a great a setup for the right applications but it does have it's limitations.
Just a little background on the Guide Gun and the GBL/SBL concepts and the adaptation of the scout scope...Guys like Jim West of Wild West Guns and Jim Brockman of Brockman's rifles had been cutting down people's standard 22" short mag tubed guns to 16-18" for years. If I'm remembering right, the original "re-introduction" of the 1895 (which was/is a reworked 336) was done on the straight grip platform and then somewhere along the way they converted the "standard 1895 to pistol grip. I might be wrong on that but I think that is right. At any rate, guys who hunted thick stuff, steep stuff, rode horses, flew planes, or what have you and who loved the power and versatility of the 45-70 were sending their guns to these guys to have them lopped off to make them handier for their applications.
The custom market for this modification must have proved robust enough that Marlin at last decided to offer a version of it as a catalog production item, that being the 1895G. The Guide Gun was so popular it remains in production today, along with the GS, and I'd hazard to guess it outsells the standard 1895 by a fair margin.
Now, the GBL and SBL concepts were essentially designed right here on MO by MO members. I don't know all the details and time lines but a fella by the handle of ORHunter, a former Marlin employee started soliciting feedback and two other members, Reflex and I have to apologize here as the other name escapes me, but those two put together their versions of a blued and stainless carbine with laminated stocks, 18" barrels, and full mag tubes. Their builds along with the feedback generated here in response to ORhunter's inquiry more or less led to the production of the rifles you see cataloged today. Pretty cool huh?
If you think about it, even the 1895G came about because of Marlin owners, of course not MO forum folks (it didn't exist then) but owners and enthusiasts all the same.
Now, to address the scout scope and scout rifle...I'm not going to say I fully understand exactly what the late Col. Cooper fully intended for subsequently controversial Scout Rifle but my understanding of it is that is was to essentially be an all-around general purpose hunting rig. A carbine that compromised in some areas but excelled in one: Jack Of All Trades. It had to be light for all day carry in rough stuff, pack enough punch to take down a wide assortment of game and at varying distances, reliable, able to snap to the eye but also be able to take shots at a distance, and so on. Obviously, within each one of those specific things, there are going to be compromises so this idea, at least as I see it, was to try to give the hunter/shooter the most flexibility to adapt to any situation as possible.
When talking about the Scout Rifle, many will invoke the old cliche, "Jack of all trades but Master of none." I reckon that is fair but it's important to remember that this is an accepted reality in the Scout Rifle and that it's intent, again as I view it, is to be the Master of versatility.
Col. Cooper had some pretty strict guidelines for the Scout Rifle and this is why a Marlin lever gun will NEVER (or at least should NEVER) be a true Scout Rifle...
1. Bolt action (.308Win preferred) - A solid reliable action but more so, it allows for the use of spitzer bullets. Again, trying to take advantage of varying ranges and the .308Win chambering being a good compromise in recoil, punch, range, etc.
2. Less than 6.5lbs fully dressed - Probably the single hardest of the specs for folks to meet. I can only guess he was thinking about guys humping the rifle all day in rough terrain and the all of a sudden an elk stands up at 20yrds or a mule deer at 200. Less fatigue and more prone to be in the hands I reckon.
3. The long eye relief scope of low power. Good for snap shooting and acceptable for longer distances. Again, a compromise setup.
4. Overall length no more than 39" or 40" as I recall with a barrel around 18 or 19".
5. Bipod. I can only assume his idea was to help the hunter with longer range shots. But a Marlin should NEVER have a bipod put on it. It should be against the law! ;D
Backup sights and all that were recommendations but I don't think one if his specs.
I might be wrong of some of what I wrote there but I think I'm pretty close. The Scout concept is not for everyone but for those who appreciate it for what it is, it is a great concept. My scout scoped 336W is exceptionally well suited for my conditions and wouldn't set it up any other way.
