2m GB3MCB - 410km: no luck at all

The mid-Cornwall 2m beacon GB3MCB is 410km away on an all-land path and, as yet, I have still to receive it, even for very brief periods. I keep looking, but without any success so far.  By now I would have expected the odd MS ping or aircraft reflection but, so far, an absolute blank.

Can anyone confirm it is on-air?

UPDATE 1900z: A very weak signal,somewhat low (144.46802MHz CW) may have been a weak ping from this beacon? Too weak to tell and no callsign copied.