While I lived in the Chicago area, I had the opportunity to purchase part of a large world coin collection that had been assembled on a date and mintmark basis by two generations of a family. Among the coins was a notebook of their coins of Germany.
I have begun listing the coins in that book in my swaplist (the 1873 A 1 pfennig is from another source), as some of you may be collecting these by date and mintmark. I will list more coins from the book as time permits.
What can I use? Nice Uncirculated Christmas coins from Isle of Man, Tonga or Gibraltar; Labors of Hercules 2 pound coins from Gibraltar; Vatican City; French Afars and Isaas; Cambodia 1953; Biafra; and other unusual locations.
I can also use emergency coins from the French colonies, and coins of the Spanish Civil War.
I generally will avoid fantasy coinages.
I collect German notgeld coins, on a one-per-location basis, but I have well over 500 locations.