Hi Richard,
Maybe I should have used the word 'easier' (referring to machining hammered cast brass compared to cast steel) rather than 'easy'.
The UK wheel cutter guy 'doth speaketh the truth' if he is thinking of a raw sand casting. A casting straight out of the mold can be rough on a cutter. Brass sand castings generally have lots of internal imperfections like occlusions and air pockets as well as extreme surface hardness caused by oxides formed when brass interacts with oxygen while passing through the molten to cooling phase. Antique brass cast back in the old days didn't go through a whole lot of quality control. These days metals available to us were poured into molds in a nitrogen (oxygen free) environment eliminating the effects of oxygen's interaction with the metal. It also goes through a bunch of hot rolling processes that eventually lead into a succession of cold rolling processes. Yawn! Finally out pops a beautiful sterile piece of perfect brass.
Hammering is akin to the cold rolling process used today only much less controlled. It hardens and strengthens the brass by making the grain structure smaller. The hardness isn't what kills the cutter but rather the imperfections and surface hardness are.
Hammering the brass not only hardens and strengthens it but also deforms the microstucture of the brass relieving stress a bit as well as reducing the effects of the imperfections. Also very important when working with any casting that will be machined is to remove that small amount of hardened surface material where any machining will be made by making a skin cut along that surface. Definitely still far from today's quality metals but far, far better than machining a raw cast part.
I personally wouldn't be too hard on that guy. Again he most likely is thinking of raw castings and how badly they will eat up his wheel cutters. At the price of cutters these days who can blame him?
True restoration of any antique horological or other demands the closest match possible to original materials and design. If that means a casting of the part is required then so be it. After all, clock and watchmakers made them this way for more than a couple of centuries so why can't we do it now if a good restoration requires it?
There's much more that can be said about this. The fact is that often times it's just an issue of economics. For example a customer may not be willing or able to pay for the extra time it takes to do the job correctly. When it's a personal timepiece then finding the time to do it might be a real problem. In that case it's probably best to set it aside until the task can be tackled and enjoyed. It's always a personal choice I suppose.
Take care over there for now Richard,
Bob