If you are selling a saddle, cutting the billets is a safe and effective way to prevent a saddle, suspected of being unsafe, from being ridden on by a future buyer, (who, if an accident occurs, might then turn around and sue the seller).
It also prevents a ‘less than honest’ repair person from oiling/conditioning rotten billets, and charging for new ones, when they suspect the customer won’t know the difference.
The saddle maker will be cutting the existing billets off at the time of replacement, so nothing lost except liability.
If you are keeping the saddle call the nearest tack stores and ask for recos for saddle repair.
Are you in London UK?
Walsall UK (2 1/2 hrs NE of London) is one of the saddle making capitals of the word, with many experts in the craft working there. Shipping your saddle to a tack repair business in that city may be the way to go.