If the fenders are attached to the stirrup leathers and the stirrup leathers are in good shape, then the fenders will be fine. They are sweat flaps. You could sink a lot of money into this saddle and it's still a sow's ear. I believe it's Mexican made. New fleece professionally installed will run between $200 and $275 depending on whether you go with sheepwool or synthetic fleece. If I had better pics I'd have a better idea of what needs fixing and what you can get away with. Undo the screws at the base of the forks and ease the seat upward. this will give you better access to where the leather wraps around the bars. Rub a wettish sponge into some saddle soap and dampen the leather, the top 6" or so. Even rub a little neats foot on it. (you're greasing it). Now, turn the saddle upside down on several towels on waterproof flooring. Pack towels into the hand hold. With the saddle upside down the leathers will fall out of your way. Dribble warm water down the leather to where it enters the tree. It will run out the hand hold which the towels will blot up. As best you can get your sponge and saddle soap as close to the bars as you can. You've done the skin side, now you are doing the under side. If there's no room make the sponge wet and try to get the water to run where you can't reach.
Follow up with a little oil. If all you have is veggie oil, use it. Let this rest over night as it takes time for moisture to penetrate deeper into the leather. If they still won't move, repeat. To help loosen them grab the leather so you are pushing and pulling at the same time. Just pulling doesn't usually work. Find someone stronger to help you. Once it moves, keep it going until the bend is exposed. Give the entire strap a good saddle soaping and oiling and let it rest a week. Give the leathers another soaping only hold the oil. It takes approx 7 days for the oil and moisture to move into the leather as far as it's going to. Let us know how many pounds of sweat you lose with this little task.