Sheet metal defects typical of this issue.
Bust type IV - the classic Bydgoszcz one used during T. Tymf's lease, but the reverse is already made in the style characteristic of A. Tymf's lease sixpacks, his A-T markings appear on the reverse. In addition, the legend of the reverse features the abbreviation AR, very rarely used on A. Tymf's sixpences.
The coin is illustrated in the catalog of L. Ciura.
Note: the book is not the subject of the auction.