Update 17.9.21: I have ordered a bunch of Si5351A's from AliExpress. Hopefully these will be genuine SiLabs/Skyworks parts, as I have read on furums about people having problems with low-quality Chinese parts having high jitter / dropping out of lock. There is also the 'official' Chinese copy, the MS5351M; by all accounts these appear to work as expected. If the AliExpress parts are bad I will try these next!
Update 19.8.21: Don't worry, this project is not dead! I am maxed-out at work currently, plus there are increasing problems with component availablility. Currently I have ~5 kits available to ship without the Si5351A-B-GT.
Limited numbers of kits are available now, however, global component shortages mean that these kits do not include the Si5351A.
Screen-Dumps Illustrating the User Interface
Additional Pictures of the Assembly
V2 Receiver PCB - Component Side View:
V2 Receiver PCB - Underside View showing connectors that mate with the STM32 board:
V2 Receiver board attached to the STM32 Discovery:
Early picture of V2 Receiver in operation: