EDIT: I have sensed a great disturbance in the Force... There is some speculative discussion regarding the veracity of the EE-3 stock Hitschmann plugs. It has been posited neither LMK nor UKW type plugs were used, rather an unnamed plug of equal dimensions to the LMK and UKW plugs. That...
I was also told somewhat recently that the ones used were neither the LMK nor the UKW, but either (A) the same sized/shaped ones as the LMK/UKW but with no markings on the outside, or (B) the same sized/shaped ones but with horizontal lines going across the outside.
How this person knows this info is unknown to me however I am under the impression this person at some point worked for and under contract for Lucasfilm and actually had hands on the prop at one point. I could be totally wrong about that though.
EDIT: Disregard what I just said... it is all in that link intwenothor linked above.
BTW: part of the reason this took so long was that the Webley was nickel plated at some point in it's history. Most processes to strip it were rather expensive (more so than I paid for the original) so it got shelved. I finally found a product that would strip the nickel at home with minimally toxic chemicals.