sharpening cross cut saws is a lost art. I have a number of books and videos to bolster my learning curve. The tools are OT these need to be searched on. Basically, these were common tools of the day and the saws can be harder to use if not done properly. A dull saw will cut better if it was sharpen properly than one done without understanding the process. I now have acquired several saws, built a sharpening frame and have ordered some of the tools. So a work in progress.
In a nut shell any bends in the saw have to be hammered out first prior to sharpening. The entire curve has to be set first, over the entire saw, on both sides, then the rakers and cutters have to be done with proper tools. It is very labor intensive. Once sharpened or even dull these are hard to handle as they will cut your skin very easily so gloves are a essential.