These are very odd moulds and probably experimental. The two long sheets (261 x 624 mm) were probably for bills of some sort leading to a decision to divide the deckle "the wrong way". I have a few moulds divided this way with a conventional wooden divider which causes a problem of formation when the wave "jumps" over the divider. The use of a thin rounded piece of brass may overcome this problem but might tend to get bent which may explain the channel set into the mould itself. Perhaps the two strips of brass support the divider better. I have no evidence of this theory and very little other information apart from the mould being made by E Amies & Son (date unknown).
© Copyright Simon Barcham Green 2011. Not to be copied or reproduced without written permission