I have just been listening to the version of Matty Groves from the Cropredy Capers box which claims to be from 1991. That year was my first Cropredy and I have my own recording of that year's Fairport set. (Yes I know. Naughty me.) On comparison of the recordings this morning I have discovered that these are not the same performance at all and therefore the version from the box is not from 1991. Does anyone have any idea what year it does originate from? It has elements of the Metal Matty arrangement but is not the full wig out that became familiar in 1991/92. It is not from '92 as that version is available on The Cropredy Box album of that year's festival. Could it be 1990? I saw Fairport that year but not at Cropredy and I can't remember what Matty sounded like that year.
There are definitely dating errors on these boxes. The version of Mystery Train with Andy Fairweather Low which it claims as 1992 is certainly from 1991 for example.
There is a 1990 Matty on the Cropredy To Portmeirion album, recorded at Brum Town Hall. It's sometimes on YouTube as individual tracks or the whole thing. I'll dig them out and compare.