The Global Index lists usages that have been used (and mis-used) globally, and can therefore be unhelpful in the UK context.

I find Kloet & Hinck's Checklist of British Insects more useful for tracking down elusive synonyms. But you would often need to know what reference book the recorder had been using, particularly if the record had been made in the 19th century as there seems to have been a large number of mis-uses of existing names (and authorities), and various other nomenclatural complications that I won't go into.

So your Strompoteryx' (sensu Auct.) is given by K&H as a synonym of Syncopacma Meyrick, 1925. And Epinotia paykulliana (Fab.) a synonym of Epinotia ramella (Linn.).

(I should mention that there is also a paykulliana sensu Haworth, which would indicate a Eucosma sp.; but I wouldn't think that would have been ascribed to the genus Epinotia - you'd need to check with a local moth expert who is familiar with the old names if you wanted to be sure - and if your recorder mentioned which reference book he used, you could compare the description of the moth - but my money would be on ramella).

Hope this helps.

Richard