Walker used the Mk III, without doubt, for his 34lb fish in 1954. Kevin Clifford's "A History.." has the pics....and yet, in accounts to the media, Walker claimed he had used the MK IV.....Hmmmm....
Kevin's brilliant book - a masterpiece in my view, also seems to reveal that when Walker and Thomas went to Redmire in September 1952, they had two prototype B James MK IVs to test....to spot this requires a little close reading, but the evidence is there, and a pic showing Walker testing a B James from the dam... the plot thickens....or at least the speculation. Then there is the Walker-built so-called Fred Belcher rod, which Kevin now owns...this is the one MK IV, as I understand it, which can be placed in Walker's hands at Redmire with certainty, in that pics exist and the cork patterns match..
Oh my head!