I would strongly doubt even 100 years old. Probably no more than WWII.... But that is a WAG.
-I disagree. Being (probably) European may blur the issue a bit, but I'd wager that thing is
easily in the 100-year-old ballpark, if not older. The curved overarm support is something of a giveaway- until about the teens or twenties (thereabouts) it was easier to cast the arm and turn it. After that, as production of bar stock improved and dropped in price, it became cheaper to buy off-the-shelf round stock, and add a clamp-on cast arbor support to the end.
Examples: Old
Brown & Sharpe mill, another old
Brown & Sharpe mill.
Key question" Are the bearings Babbitt or roller/ball)? if roller or ball, Definitely not 1800's anything.
-It's plain bearing. There's not enough "room" in the casting for roller bearings.
Considering it has a crank handle on the right end of the table, as well as the rack, I bet it works a lot like the Nichols mill. You engage the table screw and the handwheel works for fine, precise movements, or disconnect it and use the rack and lever for stop-to-stop swings for production work.
Those two holes on the left side, right above the spindle scenterline, are almost certainly where oil cups need to go, to lube the spindle. Do NOT put a zerk in there and try to grease it. You need Gits type cups and a regularly-applied oil can.
It's almost impossible to over-oil a plain bearing machine.

The only way to tell if you're over-oiling it is if your socks start getting wet.
Doc.