Haenel model IV
With thanks to Zuke.
Haenel model IV (Los Angeles dealer stamp)
This unusual standard pattern of a Haenel mod IV ended up in the US and suffered water damage. It has a very interesting Los Angeles dealer's stamp.
See also brief video below.
With thanks to Eberhard for the heads up.
Haenel model IV (May 1931)
Haenel model IV Rep (November 1928, patent pending)
Note: this rifle is marked 'IV E Rep' but does not have an export pistol-grip stock or matching trigger block.
Haenel model IV Repeater (patent pending, with export stock)
With thanks to Tim of timdysonairguns.co.uk