Hi GK,
FWIW: Just one (1) experience with many Model A cracked blocks.
Not trying to be so blunt, but in my humble opinion, driving with a leaking, cracked 80 year old Model A block can be compared to being as risky as an 80 year old driver driving with a leaking heart valve.
On the bright side, heart valves have been known to have been successfully repaired; but in some cases, a heart transplant, (aka engine transplant) may be recommended by a well experienced, cardiologist, (i.e. a professional Model A mechanic, or a well experienced, professional vintage engine mechanic.)
One can gamble with varying Guessing Game responses from different cardiologist from New York to California and from far away ...... but a serious, respectable cardiologist with a 100% track record will never make that call for repair or replacement without thoroughly examining the unseen, untested, "actual" conditions.
I knew several vintage mechanics who were past masters and 100% successful at welding cast iron engine blocks ................ and ....... there were also many highly talented musicians during those days who played several musical instruments extremely well back then .......... today ........ their sons and grandsons listen to the radio and they never touche a musical instrument or a welding rod on an engine block
Hope this helps for you to seek "Experienced Hands-On" Model A assistance to investigate exactly what you have.
In my opinion, your most beautiful 80+ year engine leaking Model A deserves as much attention as any age person deserves a cardiologist check up with a leaking heart valve.