That is either a Zinsco(Shitsco as i call them) GTE or sylvania
The panels and breakers are garbage and obsolete but used OEM and classified aftermarket are plentiful.
However, you need to consult the panel label as well as checking if there are bus stabs under those blank spaces.
Id be more concerned about a load calc seeing as how its almost all electric appliances.
What is the rating on the main breaker and what load do you plan on putting on this new double pole breaker?
That isdefinitely NOT a murray!
Agreed. It is a GTE/Sylvania, too new to be Zinsco, but does not matter still Zinsco breakers.
In a later version you would have seen it with the same Zinsco main and BR branch breakers, which just one of the reasons I call BR panels "Zinsco II".
The OP will sh*t his pants when he sees the prices of the ChiCom Zinsco replacement breakers, think they are $60 or so for smaller 2 pole breakers. They were popular because they were cheap, those days are long gone in the 35 years or so since they were discontinued.