ok so:
after finding that there's someone who is maintaining an STM32F072 USB branch, and testing it successfully to create both a usb-hid and usb-cdcacm example i put the majority of the components on the laptop STM32F072 PCB, with the exception of the 3.3v regulator which isn't here yet. i have a source of 3.3v power so that can be tested later. assembly of the much smaller STM32F072 PCB was only a day, with two uses of the IRDA lamp. i did however have to go round all of the 0.5mm pitch QFP and FFC pins individually with a soldering iron. surprisingly, QFNs tend to stick first time.
i've also ordered the laptop PCB3 which is the power board, that one is going to be fun and games, especially with the EMF from the rather large (4A) regulator. i've put in a huge number of GND vias surrounding the high-frequency power output which goes to the inductor, we'll just have to see what happens.
also i had redesigned the microdesktop board some weeks back, and will be de-populating one of the existing boards and transferring all the components. this i anticipate to be pretty straightforward, although perplexingly the microdesktop board has a staggering 120 components. i don't quite understand why, given that it's 4in x 3.5in and that the CPU Card itself is around 3.5in x 2in! still, there we go... :)
l.