Nothing secret about that. It's a common mix in almost all fine woodworking feilds, and is commonly shown in "how to" articles in wood working type magazines. There are other addatives that enhance the formula, and it can even be used as a very nice classic style sneaky finish. 5:1 seems very thin, though. 2:1 is pretty thin, 1:1 is about right. The formula is useless unless you know how to prep the wood before using, and then the steps taken after applying. Otherwise you'll end up with clogged sandpaper & a gummy shaft. Spin-offs of this formula have been used for CENTURIES & is common. Every woodworker has his own spin. Some experimentation first would go a long way if you plan to try it on something nice.
Also keep in mind that shellac is pine sap. It's hard, but softens with solution or heat. Players in warm climates may experience excessive tackiness. It also may break down & become tacky when cleaned or burnished. It's soluable in many chemicals so be careful how you clean the shaft once this has been applied. I will say it works, very well. I'm not going to give any details of use, though. I use my own spin of it.