Ringo Weltkriegsspiel

Kleissl Frederick? - Austria?/Germany?
(need to check this)

Ringo is played on the following board.

with the following setup:

FORTRESS  - The center of the board, represented above by a blue stone.
RINGS - The set of colored dots which are equidistant (diagonal equal to orthogonal) from the Fortress.
NEUTRAL ZONE - The set of red dots of the diagrams above.
MOVE - Each stone moves differently (stones can just move into one of the allowed colored dots):
Black stones - Move one cell closer to the Fortress (on the direction towards the Fortress), or may slide (with no jump) sideways on the same ring.
Black stones can just move into the neutral zone, a maximum of stones equal to the number of white stones on the entire board.
White stones - Like black stones, but can also move closer or farther from the Fortress. Also, white stones can move sideways any number of empty cells.
White stones cannot enter the Fortress, but can jump over it.
CAPTURE - A stone captures another by jumping over it (using a valid move direction), and landing on the immediate cell which can be empty of occupied by another enemy stone (which is captured). However only one stone can be captured in each turn. This seems to mean that if the piece lands on an enemy stone (which must be captured since stones cannot stack) the jumped stone remains in the board. 
Capturing is not mandatory. 
There are no multiple captures.
When capturing sideways, both stones must be on the same ring.
A stone on the neutral zone cannot be captured (however, a stone may land on the neutral zone after a sideway capture, or even start a sideway capture when staying on the neutral zone).
A white stone jump over the Fortress, captures any black stone standing there.
GOAL - Black wins if he manages to place two stones on the Fortress. White wins if he prevents Black from doing it, i.e., capturing or immobilizing all but one black stone.

An example

White can capture the marked Black stone, by jumping to cell [1] (all 3 cells are inside the same ring). After that, Black could capture by d7:f7, which forced White to capture f6:f8.

There is a ZRF to play Ringo with Zillions.

I wish to thank Robert Reid that helped me correct the rules and to point to R.C.Bell's book "Discovering Old Board Games" where Ringo is mentioned. This is a photo of that reference (the book is very small and compact so making a photo of it is hard and the picture could have been better but hey, buy it!):

(click to enlarge)