These bikes with rod brakes usually come from China or India nowadays.
Yellowjersey sold them for a few years as the Eastman Roadster, though they don't now-
Eastman made in India Classic Roadster Bicycles from Yellow Jersey
These bikes are kinda cool in a retro way, but they are definitely a bit of living in the past. The rod brakes work worse than pretty much any other kind of brake. The parts are what was "standard" on mainstream bicycles ~80 years ago, most modern parts will not fit at all. They look like an antique because they basically are.
Yellowjersey offered some optional upgrades like caliper brakes and internal-gear hubs.
The price from Yellowjersey (for the basic one-speed rod-brake bike) was only $300 but that was for a bike that was
completely broke down; even the wheels had to be laced up. For the mostly-assembled bike they wanted $600 IIRC.
Last I heard some months back, at least two other places inside the USA do still sell the India bikes, but I don't recall where. You might ask on bikeforums or even email Yellowjersey and see if they know.
This place sells a similar Flying Pigeon (Chinese) model-
Flying Pigeon LA — Flying Pigeon PA-02 Classic
does not have the double-bar frame, but that might help if you wanted to put an engine in there anyway. In the info they say they will only ship it to a bike shop for assembly, so it probably comes totally-broken down also. That bike shop assembly is probably going to cost you $150
at least.
(-the Pashley Roadster that FlyingpigeonLA sells looks similar, but is 100% modern parts,,,, with a 100% modern price-)