[Andrew2]

Bill, you shouldn't need an SDR. They are not necessarily 'better' than conventional receivers, but they are far more twiddle-able! On a good night I can hear Caroline on the better transistor radios in my collection. As we are so close you should be getting comparable reception, but I wonder if you have a high noise level? If so, can you take that nice Beolit out into the garden, away from some of the noise?
Or maybe a tuned loop antenna placed near the radio? The night-time signal can be pretty good, so you should get something.

Livewire. Manx Radio on 1368 KHz can be problematical around here. We have a local MF site just up the road (probably closer to Bill than to me) with 'Asian Sound' on 1377 KHz. If your radio is a bit wide, Manx just gets hammered to death. This is where the twiddle-ability of an SDR comes in handy.
Also on that site is Gold 1458, with a huge signal and Magic 1152, also a whopper. Could be that Bill is seeing a generally raised noise floor. A tuned loop sounds like the answer.