Ensure that the ash pan remains robust enough to take the weight of a full ash load and that there are no holes or split seams where ash could potentially leak out. Also check that where the separate handle slots into the ash pan front that this hasn't become too worn or stretched to prevent the handle from being safely 'locked' into place and eventually possibly coming out.
At Stove Spare Parts we sell a huge range of ash pans and even if you can't identify an exact replacement for your model, given the dimensions, we can probably find one of a very similar size with the appropriate handle that will do just as well.