Slugs Needed! (Or Shillings At Least)

Did that title get your attention?

I have recently purchased a circa-1990 German payphone, and am using it for a sort of art project, so I need probably a couple of hundred coins to actuate it. It's built to take the Deutsche Mark coins (10 pf, 50 pf, 1 DM, 2 DM, 5 DM), and I intend to just use the 1 DM. This still has, however, in Germany a meaningful monetary value (just shy of 50 Euro cents), so I don't expect to be able to get more than a few substantially cheaper than that.

Obviously, any coin of 5.5 grams, 23.5 mm, 75% Cu 25% Ni composition should work. And, as it turns out, there is an extremely common "close enough" coin which will actuate even the sophisticated electronic mechanism in this payphone : the British cupronickel shilling and its many, many equivalents. (In principle, it's possible to reprogram the mechanism to take anything I like, but I'd rather not run the risk of breaking it.)

Fun fact : the Guatemala 10 centavos, type of 1965-70, works in place of a 50 pfennig coin. Its weight, diameter, and composition (3.2 g, 21 mm, 61 Cu/20 Zn/19 Ni) are significantly different from those of the 50 pf (3.5 g, 20 mm, 75 Cu/25 Ni), but apparently the differences balance out, and the mechanism sees it as the same. All Guatemala 10 cts up to 2009 should work, but I haven't tested extensively.

I've tried local coin shops (I'm in Fort Worth, Texas, USA) and the TNA show last weekend, but few dealers regularly haul their "junkbox" material to shows, and the shops had remarkably little.

What I'm searching for :

• Germany 1 Deutsche Mark (1950—90)


• UK cupronickel shilling and 50 pence (1947—90)


• Australia 10 cents (1966— )


• New Zealand 10 cents (1967—2006)


• Jamaica 10 cents (1969—89)


• Malaysia 20 sen (1989—2011)


• Singapore 20 cents (1937—85)


• British Honduras and Belize 25 cents (1952—2021)


• Korea (South) 100 won (1970—2019), 5.42 g / 24 mm

All of the above have been verified by direct experiment. Bahamas 10 cents, despite being of the correct size and mass, does not work, and I suppose this has something to do with the deeply indented edge. Nor does Mexico 10 centavos 1936—46, which is supposed to be an exact match in weight and diameter, but contains only 20% nickel.

Others I have found that work in the less picky of my two phones (the other one routinely rejects half of the 5p and Aus/NZ 10¢ I feed it) :

• Finland 1 Markaa (1969—93), 6.1 g / 24 mm


• Cayman Islands 25 cents (1972—90), 5.67 g / 24.26


• Indonesia 50 Rupiah (frozen date 1971), 6.06 g / 24 mm

These were mostly a surprise.

The following I have high confidence should work, although probably only first few listed are at all common. There are presumably others still which I have overlooked. (Also I am quite sure I have many of these coins somewhere, if only I can dig them up.)

• Ireland cupronickel shilling and large-size 5 pence (1969—90)


• New Zealand shilling (1948—65)


• Malaya 20 cents, Malaya and British North Borneo 20 cents, Malaysia 20 sen (1948—88)


• Papua New Guinea 10 toea (1975—2001)


• Brunei 20 sen (1967—2021)


• Bermuda 25 cents (1970—85)


• Cook Islands 10 cents (1972—94)


• Cyprus shilling (1947,49)


• Cyprus 50 mils (1955—82)


• Fiji shilling (1957—65)


• Fiji 10 cents (1969—87), later ones are magnetic


• Ghana 10 pesewas (1967—79)


• Gambia shilling (1966)


• Malta 5 cents (1972—81)


• Rhodesia and Nyasaland shilling (1955—57)


• Southern Rhodesia shilling (1947—52)


• Rhodesia shilling (1964)


• possibly Rhodesia 10 cents (1975), although Numista credits it with a slightly larger diameter


• Samoa 10 sene (1967—2010)


• Solomon Islands 10 cents (1977—88)


• Tonga 10 seniti (1967—96)


• Tuvalu 10 cents (1976—94)


• Guernsey large-size 5 pence (1968—90)


• Isle of Man large-size 5 pence (1971—90)


• Jersey large-size 5 pence (1968—88)


• Gibraltar large-size 5 pence (1988—89)


• Falkland Islands large-size 5 pence (1974—92)


• St Helena and Ascension large-size 5 pence (1984,91)


• Czechoslovakia 3 korun (1965—69), appears to be an exact match for the 1 DM


• Surinam 100 cents (1987—2017)


• Portuguese India 1/2 rupia (1947—52)

Now here's the difficult part.
I had a dealer at the TNA show tell me, "that's the kind of material I sell for $7 a pound". And $7 a pound is a price I would be happy to pay. Postage of course raises it considerably, even within the USA. More to the point, that is the price if I'm sitting there sorting through the coins. If someone else has to do the sorting, their labour has to be paid for somehow. So why would you want to sell to me?

Frankly, unless you have rolls of 5p coins already separated for some reason and sitting around, you probably wouldn't. But on the off chance that someone might see this and say "Oh! I can dispose of this big group of circulated coins I have sitting around collecting dust to this guy!", I'm putting it out there.