I looked at an Atlantic in the UK last year which has a propane tank installed in the claimshell (or, rather in-place of the clamshell) - vehicle ran on either propane or petrol.

> On 06-Jan-2018, at 15:09, Chris S <szpejankowski@GMAIL.COM> wrote:
> 
> I like the idea. Extra diesel fuel tank? My thought is that anything heavy in spare tire cavity will be difficult to close. Got pics?
> 
> Chris
> 
>> Wiadomość napisana przez Ralph Meyermann <ralphmeyermann@GMAIL.COM> w dniu 06.01.2018, o godz. 10:34:
>> 
>> Howdy Volks.  After going with a rear spare tire carrier, I was pondering
>> what to do with that available space. I ended up adapting my home made
>> larger clamshell/tire carrier into a toolbox. I found it handy. Currently I
>> took it to my machine/Fab shop guys to make a refined design/prototype.
>> Roughly 27"x 27" the front of it has 45° angles on the sides and  7" tall.
>> The first quote was $211.  I went downs and verified a few design aspects
>> including a better sealing surface for the lid and how it fastens down. The
>> first one/prototype is currently being built. Looking at $211-$250 final
>> cost from machine shop, I don't know what shipping or anything could be
>> yet. Hopefully It'll be what I envision and be able to have them available
>> for those with alternative spare tire carriers. Storage is worth it's
>> weight in gold, Westy or tin top.