First time I've had my French marked in 45 years but fair enough. With these proportions you can't sub the Byrrh and expect the same result. Go on, treat yourself!
Maybe next festive season. I've never tried Byrrh, and from online descriptions it sounded somewhat Lillet-Rouge-like. I only had the Lillet because I saw it in stock - usually I only see the Blanc and Rose around. Having tried it in a few things I can see why it's not in the shops much.