Wasn't the Vickers a copy of the Maxim?
If so, Vickers plans might be more easily available.
I'm probably wrong on both counts of course so best wait for an expert's input.
Vickers I can manage:
Though the details are very different, the general dimensions are similar; all except the receiver was 6" tall, instead of the 4" tall receiver that the Vickers has.
(As a note, I found out that blueprint originally and can confirm that some of the measurements aren't accurate - I've a different set of plans around here somewhere which are a bit more precise...)
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
Not ALL Maxims were of the fluted barrel variety. Much easier to fabricate!
When I want your opinion - I'll tell you what it is!
Pre 1930 maxims were made with smooth barrel jackets (thats what the one in the pic looks like), a number of which would have undoubtedly been used in the GPW. Some wartime models were also produced like that as an economy measure so you're perfectly justified making it without the ribbed jacket.
I'm interested to see what you have planned for the mount, I assume you're going all the way; wheels and all?
A shield might be a good idea for airsoft, you might as well give yourself one advantage if you're going to be towing something that bulky around behind you! The shield shouldn't be too tricky to do out of metal either as its a fairly flat sheet. Plus it will sound cooler when rounds are bouncing off it. 
The rest as you say is probably easier out of other material though unless you really know what you're doing with metal and have some proper equipment.
Saw this, and thought of you:
http://www.ima-usa.com/product_info.php ... cts_id/610
Good reference photos of the mount shield.
you could email 'saracen exports'
have a deactivated maxim machine gun dated 1939, might be worth asking for more pictures of it 
Children are our future, unless we act NOW!
