Now thats really interesting.  Both have No10 on them yet both different actual sizes.

PD has some information on the Albions.  He may be able to shed some light on it when he returns.

Certainly looks like the same stamp

That join is a normal part of the casting where they have two tapered plugs which are removed after ramming, leaving a void in the sand before removing the rest of the pattern, if they tried pulling the pattern out with those plugs in place it would leave a big hole in the sand & the handle would end up without a gap under it in the finished casting.

Mick.

I checked out a few of my Albion ovens today and all the number markings related to the size's pretty well spot give or take a couple of mm.

Never claimed to be an expert but the number under the lid of an Albion oven is the size in inches.
According to the Queensland Government Library there is no record of the "Albion Stove Works"  Maryborough after 1907 so it looks like that was when they closed their doors for the last time !
BTW I saw a 10" Albion for sale in an antique shop in Dubbo the other day, fair condition .... $180 no offers.         No I didn't.

pd