You don't say if your furnance is liquid or gas fueled.

If the former, a furance of this vintage would be classified as a
'Pot-burner' and is considered to be very low efficiency.

In '69 I purchased a old house with a cast iron oil furnace. Used it for one
winter and found it to complicated to light for my wife, when I was away
from home for the beginning of the heating season.. She has to have the
serviceman come and that cost about $20..

The second season I installed a modern fuel oil furnace with all automatic
controls. Not only was it easier to operate (never had to light it), but it
was WAY MORE cost efficient. Since I did the installation myself, I only had
the cost of the furnace. I think I had the new furnace paid for in fuel
savings with in 3 years (when I sold the house).


--
My opinion and experience. FWIW

Steve