Getting good strength in a cast iron part by welding is very tough to get right - and because of heat-induced weakening of the iron's crystal structure there's only one chance to succeed. I'd go for a re-design instead where a bolted block is added the casting by machining a new flat surface in the area where the breaks are.
Looking at your picture of the broken "ear" I'd take the part to a skilled machinist. That side of the casting could be milled with a new vertical flat area, with a couple of tapped holes in the thickest area for bolts. Then a short piece of thick steel angle iron could be made for bolting to the machined surface, with 2 holes for horizontal bolts into the casting and a hole for the tie-rod. Look for somebody with a milling machine (lots of old Bridgeports out there) who does machinery repairs. The new steel attachment piece could be angle iron or a solid block. Keep it compact so the wheel can still turn to the right ok.
Here's a rough sketch of the idea: (improved 7/11) Need to disassemble the gear housing so the drilled holes can go thru. Use grade 5 bolts - about 1/2" (13mm), trim them so they don't stick out inside the housing and use sealant. For full range of motion, the block's corners may need shaving. Should be stronger than new.
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