Cracked Lower Unit Repair

[tsubaki]

You ain't lost nothing doing it the way you did.
Two concerns are if the weld is good and if the seals are damaged.
Immerse the foot for a period of hours in a drum.
Also engage the gearshift making sure the prop don't contact the sides of the drum. Keep plenty of water in the drum for when the prop throws out most of it.
Drain the foot, check the fluid for water contamination and other debris associated with the weld.
If everything comes back good less any contaminants refill the foot get brave and put it in the water and try it. Bring it back home and drain the foot again.
You get the idea.

[tsubaki]

I've seen what you are attempting work about 40% of the time.
The guy did good suggesting fluid in and the plug out.