A Cloverleaf on the Savage 99 lever boss?

I recently purchased a Savage 99 chambered in 300 Savage, and, looking on the internet, I found information giving me a manufacture date of 1949, from the serial #5105XX. So this rifle is a bit younger than I am. What's got me confused is the cloverleaf stamped on the lever boss, where I am given to understand is usually stamped with a alphabet letter.
A bit of research online has so far found me a couple other individuals asking about a cloverleaf stamping. Those were on the website of Gun Values Board. There, questions, but no answers did I see... So, what's with the cloverleaf? Anybody? Maybe it just means good luck? I've shot a few rounds through it and found the open sights were way, way off (point of impact at 100 yards is way, way too high) but as I've played with the sights I've become optimistic to think I've gotten a real winner for accuracy. Anyway I decided to order a set of Skinner dovetail-mounted peep sight and Patridge style front sight to correct that problem. I've read good things about them- and they look right.
But that three-leafed cloverleaf? Much appreciation for any help on this subject....

Can't help with the cloverleaf, but you will love the new sight!! I put one of their Hepburn replicas (not exact but their version) on an 1893 Marlin .32-40 that was factory D&T'd and love it! Sometimes those old buckhorn's don't get along with my eyes!

Big Al1, Thanks for your feedback on the sights. Funny you should mention the buckhorn sights. Originally I'd wanted to find a buckhorn rear sight, but this 99 I found persuaded me to overlook the sights on the gun as something I could 'fix'. Couldn't find an old (or new) set like what had originally inspired me. Those were on an old Winchester octagon-barreled beauty which I couldn't afford at the time. Well, the Good Lord looks out for His children and eventually, when I could afford it, I found this Savage 99. It's a thing of beauty, so slim, smooth, and well-balanced in the hands.... love it. Makes you appreciate the old school design and craftsmanship when you have it in your hand and work the action. I can really appreciate what Mad Dog has managed to collect for one of his photos I saw- so many, so good!
And regarding that little cloverleaf- one of the other examples I saw was also said to be a 1949 issue. Interesting, no?

Update on the Skinner sights: Got em, put em on this evening, and I'm really impressed by what I've got. Can't wait to shoot and get sights adjusted- just really quick with this rifle. I can really begin to appreciate why for so many it is still a very treasured rifle for deer hunting, etc.

The clover leaf was an inspectors mark they used pre-1949. Yours would be one of the last guns with this mark as your serial number puts it right around that time.

Thank for the information, Mad Dog, you are a virtual cornucopia of useful information, not to mention a great help to so many.