Something else to think about. Some older saddles do not have the larger panels that you see on more contemporary saddles. So, while replacing the wool in the panels will give you softer panels, it is hard to know what percentage improvement you are providing the horse by doing this not-inexpensive work. One issue here is that wool per se is just not as cushioning as man-made materials that were developed in the running shoe industry specifically for cushioning, like the material used in Prolite pads, for example.

As a result, you might be better off just adding a layer of cushioning between the horse and the saddle, which is relatively cheap and certainly low risk. One thing for certain is that there is absolutely no point in adding flocking to what is already in the panels — it won’t help. Either you take the plunge and strip-flock the panels, or you do the equivalent of putting a cushy new insole into your well-used running shoes by using a suitable pad to provide cushioning and disperse concussion.  This will also be more effective in solving any balance problems the saddle may have — you’re not going to correct these via flocking unless they are terribly minor. With the sort of low-volume panels on these saddles, that won’t work, and adding new wool to old, dead wool is totally pointless, as I said.