I finally began the process of going through all the doubles of my Finnish coins. In the pile that I received from my great-uncle I found my first overstrike. For the years 1928-1930, many 1 markka coins were struck directly on the 1 markka coins dated 1921-1924. The later coins were larger (24mm) compared to the new smaller 21mm coins. Thus the underlying image is bigger in proportion to the new image.

On my example, you can see the hilt of the sword at 9 o'clock on the obverse. On the reverse you can see the underlying "1". I have included links to larger images where you can see the text "markka" especially well on the reverse, between 2 and 5 o'clock.



obverse
reverse

How common are these Sisu?!

Now you got me tempted!

Not too many countries attempted overstrikes and I didn't expect Finland to do overstriking at such late era.

There are no actual figures listed. But using the prices in the Finnish Numismatic Society's catalogue, the 1929 is the most common (priced near 2x that of a normal strike), the 1930 less common (priced at about 3x) and the 1928 is very rare: only 2 known examples (no price given). Accordingly fakes are known to exist.

Very interesting. Were the overstrikes because of scarity of materials or just reprocessing coins in the Mint's possession?

Mostly the latter. During the years that the larger 1 markka coins were minted, higher denominations were needed for commerce but were not being minted. When the necessarily legislation passed and the coins were designed, it was decided to reduce the size of the 1 markka coin to better differentiate it from the new 5 markkaa coin (different in color as an aluminum-bronze, but too close in size at 23mm).

Sisu, do you happen to know what the year of the underlying image is? I am more than interested to know what it can possibly be

I have tried already. I looked and looked, but I cannot see any underlying date. In fact it may have even been part of the coin that was cut when making flans for the new coins.

Sisu, I am trying my best here but it seems that the year MIGHT be visible!!!

I can most definately see the third digit "2" but other than that, it seems a bit "blur" from this picture. I believe there is a possibility that you might be able to find the last digit!!!

A rough draft on a quick sketch - (sorry I am getting a bit sleep here, will try to work on this the next day)

Edit: Link

It may seem that the paws are unusually large but this is usually a symptom after an overstrike event.

The digit 2 seems to be near the sword area but after I did some basic trig, it may seem that the last digit might not exist in the first place

I was thinking that it might have been a 1922 but the last digit might be the third from what it might be