front Bumper alignment

[el_bole]

Got my slow build onto the next step;

Need/want to weld on original "front end"(1961) onto my 73' frame.

What's the best way to go about this? I C -Notched my frame and big some body panel work but I don't want to F&*# up this particular part LOL

Any and all advice would be greatly appreciated.....Attached are pics of what I will be working with.....(original front frame rail ends on work stool).....Also please consider that the frame railing is narrower on the 73' so it will have to be "widened" so that clip sits correctly(how do I strengthen it?). Thanks in advance fellas....