wow... she's been burning wood alright (as soon as you start burning coal the inside, window, etc. will become clean as a whistle)! almost any coal stove can indeed be used to burn wood, but I am here to tell you the model 88 is really a pure 100% coal stove (you could indeed burn wood inside or anything else for that matter, but this stove is a pure coal stove no matter what my dad put on the label
). This stove is a solid welded beast and it can hold up to just about anything you throw at it. You currently have a Pea size coal grate that appears to be in fantastic condition (the whole stove is in great condition actually when looking at the upper baffle, top plate, etc... all tell tails this stove has never seen tough duty). It does appear your firebrick near the grate is worn (large gap between grate and brick)... for this reason your going to want to use Nut size coal (which will work fine with the pea grate)... the only warning I will give you is the slide handle on the pea grate (the part you attach the shaker handle to)... is not as strong as a nut grate so use care when shaking it down (nice even back and forth motions and don't force it), a lot of people will open the bottom door briefly to heat up and soften things just prior to a shake down. This firebrick is in great shape other than the area near the grate (If you wanted to repair that at some point I would simply take the grate out, clean it/wire brush it well and "butter that area").... I know others might not like that advise but on this stove the firebrick is very expensive and this a solution that can work for many good years (cheap & easy).
we have the owners manual for this model posted here Copy of manual for Crane 44
, model 88 is same as model 44 (just taller).