Brandenberg, Germany, 1912 - 1930. Founder G.K. Gundka made small mechanical toys; mid-1920s appears to have been the height of their popularity. Often marked "Gundka Werke" or with G.& K.
What's your 'Greppert' worth? Here are some recently sold items (Canada):
|Kelch Motorcycle Works Fine Germany||07/2019||C $1 957.61|