Hi Sgt Shultz,
Just came across your M3A1. I always like this vehicle, it's quirky if you know what I mean.
Excuse my ignorance but what period, theatre of war are you setting the tank in?
I don't know much about the specific details of this particular tank so can't comment there but on the finishing side it looks a might too clean for me. Try using some MIG pigments to add a bit of weathering. If you like you could draw the rust down a little with paint and thinner/ white spirit.
Rubbing the edge of a surface with a lead pencil will give the effect of light wear on the edge and it's pretty cheap. Try it on a few rivets and see the effect.
If you haven't used any of the MIG pigments before they are well worth the money.
Try adding a few bits of kit around the tank in different places. Crews always hung stuff on the outside as there was so little room inside.
If you add it to a small dio then you could add a figure or two for interest.
Is one of the straps hanging loose at the back?
Just some thoughts - seems like a nice clean build but with a little added work you could make this an interesting vehicle.
Hope this helps and thanks for posting the pictures.
Cheers
Al