By the looks of your drawing and considering general engineering principles, that repair is no use at all. All the weight of the knee will be trying to bend the repair angle, so the dovetail is flexing outwards.
When cast iron cracks, it usually goes together very well afterwards, and really, it is better to do the repair mechanically, rather than resorting to either welding or bronze welding. In industry you would call in the repairers to have the cast iron 'stitched' together using tapered wedges that cross the crack, and when driven in, pull the break together. But that usually costs a fair amount, so maybe you could have a look in Yellow Pages, you may be lucky and find someone to do it locally, they usually charge by the number of 'stitches' required and whether you can get the job to them, or they come out to you. I can't quote prices because it was a fair time ago, and I never had to pay the bill anyway, that was sent directly to accounts.
So, if that isn't possible, you need to take the strain off that repair bracket and make the repair more stable.
If I was doing the repair, going on what you have shown, I would take out the second bolt down and drill the hole much deeper, actually so that it penetrates to well beyond the crack. Drill out the beginning of the hole, to just past the crack, a clearance size for the bolt to be used. Then from the bottom of the clearance hole, drill and tap for a good strong thread, Whitworth, UNC or Metric coarse, then pull the crack together using the bolt. That would need to be done to well past the crack depth down the dovetail, just to stop it cracking any further.
Just my take on the problem.
Bogs
