I have booked, rather to my own surprise on reviewing my itinerary, two separate tickets (that part was inevitable, discount carrier Norwegian Air is first carrier) with 2:05 connection between airlines at LGW, South Terminal. That's counting on the first flight arriving nearly on time, which was probably a mistake. (Most recent performance is 0:40 late, 1:10 late, and 3:50 late, which I bet involved turning on the afterburners to avoid the compensation due at 4:00.)
Our luggage is small enough to be taken as a carry-on, but in theory it is probably over Norwegian's 10kg weight limit, which includes the additional laptop bag. I feel I will have to make a game-time decision whether to check bags, adding to time needed to transfer, or hope they aren't using scales at the gate. How much additional time will baggage reclaim take, given that we have to go through immigration (USA passports) anyway? Will the bags likely be waiting once we clear the passport examination? (We don't need to re-check the bags, as British Airways' weight allowance is much larger.)