A Ford F60S with a No. 43S cab to be precise. Here's a pic of what the front of the truck looks like and some background...
"The No 43S cab was a special cab used only on the Ford F60S-BOFORS anti-aircraft truck, essentially a self-propelled medium AA gun. This cab was a widened No 43 which allowed four abreast seating of the vehicles crew, all available space on the rear of the truck being taken up with the bed mounted 40mm Bofors gun, ammunition and gun stores. The four abreast seating was unique in that the driver remained in the conventional position with a passenger outboard of him and another two passengers on the left side of the engine. No roof or doors were fitted to No 43S cabs. This cab also has a conventionally sloped windscreen. The discs attached to the front cowl on the truck pictured at left are two of the four base plates for the vehicle's levelling jacks, two of which can be seen on the front bumper and under the body just rear of the cab. The fuel tanks on these very interesting CMPs are fitted transversely in the body behind the cab."Those are both from this page...
http://www.users.bigpond.com/ROD_DIERY/CABS.htmlHere's an impressive picture which shows what's missing from the truck in the museum...
http://www.oldcmp.net/refindex.htmlOn it is a link to this page which has lots of pics of F60S's in varying states of disrepair...
http://www.oldcmp.net/f60s.htmlWhile you're there, check out the main page of the site. It's dedicated to CMPs.
A bit more history. The truck is a CMP...Canadian Military Pattern. Built in Canada by Ford. Chevy also built them, sharing some interchangable parts. The right-hand drive is, as this page states...
"Curiously for a North American designed and produced vehicle, except for very early prototypes, they were all built in right hand drive, a legacy of Canada's 1930's adherence to British defence policies."That and more history and truck specs here...
http://www.users.bigpond.com/ROD_DIERY/HISTORY.htmlHere's the main page for CMPs on that site which ahs tons of info and pics...
http://www.users.bigpond.com/ROD_DIERY/cmp.htmlHere's another impressive picture of a fully equipped F60S Bofors...

It's from this forum page...
http://www.mapleleafup.org/forums/showthread.php?s=feec1dc9aac4fc0146f173047a4b36d8&threadid=492Which is on this site about Canadian Military hardware. Here's their main page about CMPs...
http://www.mapleleafup.org/vehicles/softskin/index.htmlIt has some more great pics of the F60 Borfors. I just noticed these are F60Bs. Maybe that is what is in the museum. Hummm....the messages in the thread discuss which thy might be. Well here are the pics anyway...



All from this page...
http://www.mapleleafup.org/forums/printthread.php?s=27283f22cf051fb04be9e6628422f448&threadid=2598&perpage=40&pagenumber=2Well, maybe it is an F60B. Here's a B from the Danish Army...
http://www.armyvehicles.dk/fordf60b.htmOh just found a reference to the truck by someone who sounds like they would know. They say it's an F60B...
http://www.mapleleafup.org/forums/showthread.php?s=f66f6d0d1fc5f3cb45a45c674bfc6788&threadid=2624&highlight=f60bTanxheaven has some great shots of a Bofors...one which has an F60S in the background...

It and the rest are here...
http://tanxheaven.com/ljs/bofors40mm/bofors40mmljs.htmHere's a better shot of the truck...
F60S,Volkel.JPG)
Which is from this page which contains more pics of it and lots of other similar vehicles...
http://tanxheaven.com/ljs/truckscanadaljs/truckscanadaljs.htmSo any models of it? Well, I only found one...a 1/76 scaler...
http://www.smallscaleafv.com/ANG/Novinky4/76_CMPBofors.htmlApparently there was a triple Oerlikon version too...
http://home.hccnet.nl/h.van.oerle/gies/gies3.htmI even found an experimental with a triple Polsten gun mount...

It and more 20mm guns can be found here...
http://bcoy1cpb.pacdat.net/20_mm_aa_guns.htmIf you want another scale, it looks like scratchbuilding time. Some drawings might be handy...
http://www.geocities.com/firefly1002000/1_35.htmHere's the layout of the frame and drivetrain...
http://www.oldcmp.net/fordmanuals.htmlHere's a page with a large drawing of the layout of the hardshell version of the cab...
http://bcoy1cpb.pacdat.net/cmp_canadian_military_pattern.htmSo, what is this one?...

Warning...I don't have a clue, but thought it was interesting. Here's the reference page...
http://mailer.fsu.edu/~akirk/tanks/Venezuela/Venezuela.html