Yes, it's done! And yes, it is a complete success.
Lorelei is the London Town Bike, on the road the whole of this past winter. She's a pleasure to ride and completely reliable, having needed not so much as a brake cable adjustment in the past five months.
Petra is the Modern Retro Road Bike, on the road for the past two weeks and just a dream to ride.
Lorelei has the original factory-spec Simplex 10-speed gears (48/42 crankset with 14-28t cassette) and Weinmann brakes. Wheels are 27" x 1-1/4" shod with commute-proof Schwalbe Marathon Plus tyres. Stem and handlebar came from the now-decommissioned Viking Bromley. Saddle came off another de-commissioned bike, Adam's old commuter. Mudguards are SKS Chromoplastics; the rear rack made by Blackburn. Lorelei's pedals are just about the biggest platform pedals you can find (like BMX pedals but without the spikes).
Petra has a semi-hybrid groupset: a 50/34 compact chainset with 160mm cranks from Spa Cycles, a 9-speed 12-28t cassette, Shimano Tiagra front mech and Shimano Deore rear mech. Wheels are Mavic rims in 700c with 28c wide tyres (Vittoria Rubino on the front, Conti Gaterskins on the rear). Stem and FSA Compact handlebar came from the Surly Pacer that I sold in 2014. The Selle SMP Extra saddle was sourced from Ebay. The mudguards are Madison's Primoplastics. Petra may get a rear rack at some point. Pedals are touring pedals, possibly the most elegant I've ever seen (brand unknown).
Each bike performs beautifully and each plays its own unique role in my 'stable'. I would be very pleased to have either of them on its own. But having two like this -- identical from the factory yet now so different from each other, yet each perfect in its own way -- gives me a great deal of pleasure. We have at least two re-location upheavals ahead of us in coming years and there may be some difficult decisions about which bikes to keep and which will need new homes, yet I see these two both staying with me.