Hi John.

I've not seen any of the later variants marked "Milbro". I was hoping more will come forward to add more examples to build up the stats a little.

When you say "shroud" you realise that I meant the plastic insert/bush at the end of the tube where the front sight is. Or do you have yet another variations where the spring shroud that covers the spring beyond the end of the compression tube is plastic? Now that would be a turn out for the books. Do you have a photo? Unless someone has replaced the metal shroud with a plastic part - unlikely but not improbable.

I think that what I called a variant 4, with the steel pillar front sight, should be variant 3 and the bladed front sight model perhaps variant 4 if Malcolm's theory of model numbers is anything to go by. That could mean a plastic barrel insert/bush would possibly be a late change to the variant 4. Maybe, who knows!