All I can say is I'll be buying a couple of each livery. If they are as good as the 141s, then they'll fly off the shelves.
I've been waiting a long time for MM to do the 121, and wasn't happy when there was talk of them not being done. They'll be sweet whether they run single, in pairs, or mixed with a 141! Hopefully we'll get 124 & 134 in the IE livery, as they ran together so often towards the end