A few years back I saw an article on Paul's excellent Plastic Warriors Website on using a cut-down Airfix 88mm Flak to make a 105mm US howitzer
http://plasticwarriors.blogspot.com.es/2010/06/m2-m101-105mm-howitzer.html
I needed a couple of these for my WWII US forces and inspired by Paul's original idea, I decided to put a couple of old Airfix 88s I had in the stash to good use.
The barrel of the 88 has been cut down and the shield comes partially from an old Airfix 6 pounder AT gun and the rest was made using some cut-down clear plastic sheeting.
The axle and wheels are from a trailer that comes as an accessory with a die-cast Altaya M16 Half-Track. The trail legs are flat plastic cocktail sticks.
Yep, it's a crude "representation" and it would probably raise a lot of eyebrows at an IPMS meeting, but I think once it's painted and on the table it maybe won't look too out of place.
I'll try and get this painted up and will post a couple of shots soon.