In these COVID 19 days we wonder whether there is a difference how quarantaine (or self isolation) rules work between the different modes of transport.
A search of https://reopen.europa.eu/en indicates that there are no countires in the EU in which quarantine rules are dependant on the mode of transportation used.
The UK's quarantine applies to all ...
I'm not sure what you wrote the first time, but I'd recommend writing to Deutsche Bahn a time or two again. You might get someone more interested in preserving customer goodwill over an honest mistake rather than mindlessly following the rules.
Make the following points:
You intended to buy the ticket for your son.
You chose a fare appropriate for your son....
As the standard answer states, Super Sparpreis tickets are neither refundable nor changeable. This includes the travellers name. If you're lucky, you might get a refund out of goodwill. I wouldn't count on it.
Basically your son would be dodging the fare, which would at least cost 60 €. Again, some conductors may act on goodwill if explained the issue. Again,...
Good news: there's a plan to refurbish a Settebello train and bring it back to service:
“Settebello” electric multiple-unit: the refurb has started. Coaches 6 and 7 will be redesigned thanks to the collaboration with DIT- Laboratorio Design Italiano (Italian Design Lab), who will propose projects incorporating the most advanced technologies available
Marlow in Buckinghamshire can only be reached via Bourne End, which can only be reached via Maidenhead - 2 changes from London Paddington.
I suspect this could be the nearest, about 30 miles away and less than 1 hour total journey time from London Paddington.