I certainly understand your desire to economize. First of all, my machinist told me that these valves are now available on the aftermarket and are much less expensive. You might start calling some foreign car supply houses and see what you can come up with there.
Secondly, the majority of valve reconditioning labor is grinding seats and valve faces.
Also, my machinist took a lot of time to remove the prechambers and resurface the head. I expect that this short, cast iron head is not prone to losing its flatness. Get them to check it for straightness and skip that step if you can.
Summary: It seems that most economic way would be to check for straightness, find aftermarket valves and pay the machine shop for guide replacement and seat grinding. With new valves you may get by without grinding the valve face. I'm not sure, but it may be standard procedure NOT to face new valves. Hooking up the valves yourself would save very little.
Let us know how it turns out.