I think it is now generally accepted they are genuine, but the location of the mint is the one uncertainty. The combination of a large plume mintmark would be in keeping with the Chester declaration reverse and the Chester unite, which would have been struck around the time of or shortly after the closure of the Oxford parliament in April 1644. The President of Wales had a large plume as his emblem. We know that Rupert left Chester on 20th August 1644 and arrived at Bristol on the 26th, so if the coins were ordered to be struck by Rupert in his capacity as President of Wales, any Bristol related detail such as the declaration should post-date the 26th Aug with a terminal date of 30th November. This is why the documented coining at Hereford in Oct 1644, the arrival of Gerard at Hereford in the same month and the over-wintering of his troops in the Hereford and Monmouth areas is so compelling an explanation. However, it doesn't exclude the possibility that the coins were struck at a few locations over the surrounding area given they were dispersed for the winter months. Yours was found at Goodrich(?), where the castle would be a logical billeting point.