Answer:: 80's road bike with modifications
I'm guessing its an 80s road bike that has had the drops, quill stem, shifters and brake levers swapped out for a flat bar from a more modern MTB.
That's a gorgeous steel lugged frame
No bottle mounts are in the frame, which is why a PO has fitted a strap-on bottle cage.
Frame pump mounts also went out before the 90s, as did the uselessly-short mudguards.
That rear light looks like its powered by D batteries. so will be heavy. I'd swap it for a pair of efficient LEDs, for safety when riding at night, unless you're trying for a period bike.
The cranks are cotterless, so its no older than the 80s or that was also changed - there's a triple chainring, which may have been fitted with the MTB bars or may be original.
There may be more info in the rear cluster/cassette and the rear derailleur, and the brand/model of brake calipers.
If it runs okay then air up the tyres and ride it. I'd suggest changing all four brake pads, and examine the tyres for deterioration.
If the tyres are getting iffy, consider replacing the whole wheel with a more common 700c aluminium rim. Those 27" wheels look like chromed steel and wet weather braking is wishful thinking! Downside of this is the brake calipers may no longer reach a slightly smaller wheel and may not have as much pressure under braking.