Reporting back here after trying the Hobson's drag choice for dynamic partitions in Macrium Reflect. Three dynamic partitions, including System, dropped into the new SSD, but the C: boot dynamic partition 'copied' only a phantom partition, i.e., it was empty.
Then, following a tip from my supplier, pp.co.nz, I tried EaseUS Partition Magic, the now Chinese-owned old programme, and without any fuss, like dragging partitions, it worked like a charm. All four dynamic partitons migrated, and in the process had been converted to Basic partitions.
I highly recommend reasonably priced EaseUS Partition Magic, not only for the efficiency of the software, but also for the efficient, polite way in which the company's Help desk dealt with my enquiries.