I don't really know enough to be dogmatic. I would suggest that some harpsichord makers have been dealing with this problem for some time and may be able to help.
I've only had to make one. I modelled it in dental wax; mould made from an automobile repair kit product from the local filling station; and used a resin/brass mix for the cast. It was adequate but nowhere as good as I would have liked. I was tempted to gild it using leaf but thought that too much detail would be lost. My own instrument has a wooden one. Has anybody traced any developments or changes in roses? - The industrial revolution was very busy in the second half of the 18th c. In 1769 John Pickering in London took out a patent for stamping certain articles from sheet metal - coffin furniture, buttons etc. Other patents followed elsewhere within months. In 1779 patents were taken for producing similar articles in rolling presses. I have always understood that EG roses were stamped. However - Casting delicate objects in brass is first mentioned at the end of th 17th c. for thimbles, and would have been used in the button, buckle, toy and rose(?) trades. So perhaps some at least were castings? Ithink that some of the extant roses were varnished to imitate gilding. Others were certainly gilt. This would have been mercury gilding at this period. Gold powder or leaf dissolved into or emulsified with (I haven't tried it) mercury; painted on to the brass; the mercury driven off as vapour. Poisonous and highly dangerous, and a very commonly used technique. Almost certainly the roses would have been bought in, probably from a very small number of makers, in the same way as clock faces were nearly all made by one or two makers in Birmingham at this period. There is a very limited number of designs, and several elements are common to different designs. Peter To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
