Garibaldi Shirt making - Collar mock up

I've been trying to figure out the collar for my Garibaldi shirt. The standing collar from the Simplicity shirt pattern I'm using to 'Frankenstien' parts is too small for me, so I've had to work out how to make it bigger. I basically just extended it from the fold, and it seems to be ok.

Trouble is, I have no idea just how tall a Garibaldi collar would have been. What I have made stands about 5cm tall. Is that too high I wonder?