Here is the perfect example of another "Closet Collector" who is not known to our mainstream collector circle.
It does not surprise me. There are many more of these collectors out there in the U.S.A. who are basically "unknown" collectors that I, and others refer to as "closet collectors". They basically do not attend shows and keep their collecting very quiet and they do not participate in known collector forums such as this one or other ones that exist.
They may have accumulated their collections years ago via garage sales, estate sales, auctions, gun shows, and even via mail order catalogs or auction houses many years ago.
They have quietly collected for many years or decades, and only their immediate family probably knows about their hobby of collecting pickelhaubes. I can imagine there are many more out there who are like this collector who are an "unknown collector" and fly under the radar with our group here.
The collection a few years back that was purchased by Regimentals from an unknown collector here in the U.S. when Malcolm Fisher and his son were at a S.O.S. is another example of a "closet collector" who seems to be unknown within the famous collector circle here on this forum, or from Steve's fine and extensive experience of collecting since 1970 and knowing all of the well-known collections in the U.S. since that time period. There is a whole different world of collectors out there who don't go to shows and don't participate on forums, and who are basically unknown to any other collectors.
Every time I set up at a flea market or antique show or a gun show to fish for leads on helmets I always run into a large number of quiet "unknown" collectors who are out there in seemingly every little town in the midwest part of the U.S. They don't all collect pickelhaubes, but they all seem to collect some sort of military items, whether it be U.S. WW2 or WW1, German 3rd Reich, or whatever type of military object. It might shock anyone here to see how many small collectors there are out there all over the U.S. who are basically "unknown" to anyone else.