First off, buy the item you have shown if you not done so already.
It is a handstamp, not a machine.
Jim Forte has the following Represa CA doane for sale:

Note the differences between yours and his:
1. the lettering is a different size and spacing from the rim.
2. Forte's doane is a true type 2 doane with 4 paired bars. Yours has 6 paired bars, thus a doane mimic, unlisted on Gary Anderson's postal history website which is where I go for doane data.