Since you're just considering to sell it, let me persuade you not to. I have one in 6.5CM myself and have done a lot to it. I think that, if dressed well, you may be more inclined to keep it. Or at the very least, this will serve to motivate someone to buy this from you.
After doing a lot to mine, I think that me getting the Vortex Razor HD Gen 2 3-18 is the
primary way that I went wrong. Not because of magnification, but due to weight. Rather, if I got Vortex's new series, the
LHT 3-15, that would have made a better match. While losing 3x magnification, the near 2 pounds of weight reduction makes that configuration a true battle rifle.
One thing that
I absolutely do not regret about the way that I dressed my MDRX was putting
an offset HS509T on it, using an Arisaka mount. The "D" in MDR should be taken advantage of. Even with the 20" barrel that I have, the overall length is still just at 30", which makes for still a pretty tight package that is useful for turns around tight spaces; and of course, offset red dots shine in tight spaces and corners. Moreover, the offset, when partnered with a mid-range optic--that tends to start at or above 3 power--there is no unutilized potential left from the MDR platform.
The
second best thing that I did in dressing up my MDRX was attaching the
Fab Defense foregrip to the tall and thick, and otherwise unergonomic, suppressor compatible m-lock handguard. With the included thumb lever, the handguard becomes just as controllable as that of an AR 15.
The
second worst decision that I made in dressing up my MDRX was buying a non-QD bipod. I bought the Atlas B10 V8. It should have been the QD version--mainly because, although chambered in 6.5 CM, the MDRX is not primarily a sniper rifle. The bipod adds a noticeable amount of felt "drag" to pivoting the point of aim. Basically, I think the bipod is great for zeroing, target shooting, or maybe even hunting; but, for all of those situations, the assurance of a fixed bipod being on the weapon is really not necessary, because deployment of it in these situations is not significantly hindered by the added 5-10 seconds needed to reach into a bag pocket for a QD version. On the other hand, for the majority of emergency circumstances where the fitting choice of the MDRX made, the weight and space of the bipod would be a hinderance. In short, I recommend that an MDR owner
buy a QD bipod to keep in a range bag, or go-bag if for an emergency situation at all.