Is it me or has the online refund application form
(http://www.tfl.gov.uk/tfl/tickets/refunds/tuberefund/) been changed to only
accept Oyster ticket numbers?

It wouldn't let me proceed without (specifically) a 13 digit ticket
number...

I'm trying to make an application against a paper gold card (Which I was
able to do a week or so ago online)

I shall give the folks at LUL Customer Services a call tomorrow and see what
they say - I don't expect to have to process my refunds on paper forms again
just because TfL want everyone in London to use Oyster without exception.