Hi Mick,
Yes there had bilge keels on the real boats, primarily to allow them to dry out and stay liveable on between tides,
The main reason I use a detachable keel is for folks who may want to make a static model, the bilge keels are not very much use for sailing but are practical, real yachts with long or fin keels point much better.
As to adding weight to the central keel as it is on the fullsize and the bilge keels is all about the righting moment in a knock down, so the deep bulb keel is just better for performance. glad to hear your enjoying the build I know a few others are on there way.
My next yacht will be the Spring 25
Regards Ray