Catching a flight on Norwegian from ARN (Stockholm) to OSL (Oslo).
Then catching a BA flight to LHR.
(2-3 hours after landing before the BA flight)

Just had a quick look at departures and it had Norwegian around Gate 15 and BA around Gate 53.

Ideally want to be travelling with hand luggage but I'm sure it will be a little above the 10kg limit Norwegian have so it may have to be checked.
(Was 12-14kg last time it was weighed by BA/AA and expect to be carrying a similar amount this time)

Assuming either scenario, how long, roughly would it take for me get from one plane to another?