Well, the 57 cm Pro Connect arrived today. Unfortunately, however, no keys arrived with it!! Phoned 50 Cycles. A process then ensued of trying to determine if the keys had fallen off the bike in the van that delivered it - but they hadn't. So where the keys are is anyone's guess. Given that they are supposed to be securely tied to the handlebars with a zipped tie, my bet is that they are still at Derby Cycles in Germany.
I was not too happy with 50 Cycles original suggestion that they send me the one and only spare key (which is hard to get copied apparently). However they have now agreed to send me the key and get me a replacement battery lock, together with a full set of keys - quite happy with that.
Bike looks great and has been ridden, unpowered, round the block. Very impressed with how easy it was to ride unpowered - Hopefully key will arrive tomorrow and I will be able to charge the battery.
Not the start I had hoped for - but at least I've finally got it. Also pleased that the size is absolutely perfect for me - I had a slight concern that it might be too big.