Any ideas what vehicle these are for?

[Herewego]

I came accross these fire extinguisher brackets (I think thats what they are). Could anyone tell me exactly what vehicle they are for and if they are rare? They look too beefy to be for most of the smaller military vehicles. Thanks in advance.

 

[gimpyrobb]

I had one mounted in my 67 M725.

 

[NDT]

Looks like oxygen/acetylene bottle brackets for a SECM body.