Thank you Malcy,
I found in the same Hull book a /90 Pearl Gray Lizard Skin, which is not so far away of the 'silver' you mention. If FmrLEO_GJ could find about the nib size or an eventual number we will get closer to which pen it is.
I continue to believe the one from David is /89 Garnet Lizard Skin because of the garnet lines, when we find out form him, as offered in his last post, the nib size and a number from the barrel we will get closer.
It is not the first time I have been stocked with this strange numbering system from MT, so the best is certainly to keep on looking for answers.
In the Hull book also (maybe you have i or know it: The English Fountain Pen Industry) there is a line saying: "A number of 'non-standard' Leverless Lizards are known to exist, including an L312/90 (Pearl Lizard Skin) with one-piece (slightly conical) cap/inner-cap and side slot RG clip, and a Green Lizard with a No 2 nib, without cap bands."
Just after reading your post I visited the Swan section in e bay I saw a Green Lizard Skin offered there, it is a darker green as you mentioned and a very different green too not pale at all.
In any event thanks for your response, it has been a step forward.
Regards
Edited by Penmex, 04 April 2012 - 09:15 PM.