How can I solve a Gronsfield Vigenere combined cipher?

I understand how a gronsfield and a vignere cipher work, but I can't figure out the gravity falls vigenere combined cipher works. I tried forwards and backwards neither works, here's the code: 4-19-10 5-25-11-22-9-5- 8 12-23-21-19-20-23 6-9-3-10-20 23 1-16-19-19-12, supposedly it says: Ten symbols placed around a wheel, the vigenere key word is (Shacktron). Online decoders don't work, I've even tried the wheatstone cipher. Ideas anyone?