Dear Hugh,
I've never heard of a clubmaker named R.A.C.O. or seen a putter marked this way. However, putters are frequently personalized for corporations as a corporate outing promotional item, and perhaps this is a generic putter that was part of a R.A.C.O. outing. Here are some suggestive leads:
A RACO Industries is located just outside O'hare airport, Chicago, that deals in used metal working machinery, including CNC machinery. They've been around for a long time and it would be very easy for them to stamp their name into a putter or to make a putter or have one made. I've sent an inquiry to them to see if they know anything.
http://www.raco.com/
There is a RACO Industry in Cincinnati at the Cincinnati / Northern Kentucky Airport that makes Global Positioning System navigational devices, and this company has a line of golf-related products. I've also sent them a query.
http://www.trackmyvehicle.com/contact.htm or
http://www.golfersweb.com/golfcinc/
In Emeryville CA, a RACO Manufacturing company makes remote monitoring and alarm systems. They've been around for about 50 years, but somehow I doubt they are the ones.
http://www.racoman.com/ or
http://www.expo21xx.com/popup/7540.htm
Probably the most widely known company is RACO, a division of Hubbell that makes electrical boxes for contractors and electricians. RACO is sort of the "Coca-Cola" brand for this industry and is present in every electrical supply vendor in the country and probably the around the world. They used to be independent, but were acquired fairly recently by Hubbell Electrical products, a large conglomerate. I don't really know any more about them, except their HQ is in South Bend, IN.
http://www.hubbell-raco.com/
It would be helpful if you could give me more details about the putter -- such as whether the mark is "R.A.C.O." or "RACO" or "RACo" or some variant; whether the putter is fairly new or about how old it is; what part of the country was it found in; how was it acquired; what sort of design does it have; are there any other marks on it. Perhaps the person who asked you can contact me directly and I can pursue the matter deeper.
In the meantime, you might try contacting Chuck Furjanic thru his website Golf for All Ages,
http://www.golfforallages.com/index.html. Chuck's email is furjanic@directlink.net. Chuck is located outside Dallas and deals in all manner of old golf clubs. he seems to answer question like yours as a matter of helpfulness, so give him a try.
I'll wait for more info or please let me know if you get any help from Chuck. If I get a reply from either company above, I'll send it right along.
Cheers!
Geoff Mangum
The PuttingZone
http://puttingzone.com
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