Questions about the Porter from FSD

I'm waiting for my registration to be approved at the FSD forums, so I thought I'd ask here while I wait.I purchased this a week or so ago and have just started using it with Cargo Pilot that I've just purchased as well.While looking at the specs of the plane, in particular the weights, some things don't make sense.Has anyone else noticed that the weight limits seem a little off with this porter? FSD has the MTOW close to 4800 lbs, I believe, but from my research, it appears this model should be about 6173 lbs. There are a couple different models-- one with a shorter wing span that does have a 4800 MTOW, and the one modeled my FSD that has a 52 wing span that has the higher.Anyway, If I hadn't started using Caro Pilot, I would not have become confused as I'm looking closer at weight limitations. The numbers just don't add up for me as far as Cargo capacity and gross weight are concerned.So, does anyone have any experience with this?Maybe I just need a lesson in weight and balance..lolThanks :)