I can heartily recomend the Mk 3 oil can for use when travelling.
The two on the far left are plastic and quite brittle compared to modern stuff, which is a shame as they are the most commonly available now. the next 4 are cheap wartime variations that are becoming increasingly rare, also they some times leak. The green paint on one of them just signifies (up to the 60s) that it was meant for the low tempreture version of the gun oil for winter/artic use. The 4 on the right are all brass, either nickel plated or painted with green enamel. The Australians and Canadians made them through out the war so some can be a bit rough/leaky but i've never had a post war one lose oil. The UK nickel ones tend to be dated post war (a 1939 one would be a real find).
If you require something a bit bigger The Can, oil, M.G. Mk I takes about half a pint and still has a brush attached to the lid. Up to a few years back you could pick them up for next to nowt. If you find some, give them a good shake as they sometimes rust internally while in storage, being made of steel, but you can hear the flakes rattle about in a bad un.
Again wartime ones are more likely to be leaky than post war. Because of the particular conditions they were operating in Borneo the Aussies had a even bigger oil bottle, still with the brush fitted. The stanadrd quart water bottle had the spout removed and replaced with the cap assembly off the Mk I oil can.
There's plenty of other military, tough, oil containers but these are the ones I know of with brushes.
I'll get my anorak...
ATB
Tom