It was common years ago that the team mechanic would do all the final frame prep procedures like chase and face, ream and face and such on new frames. But I sure don't know how well prepped the frame you have is. Certainly the chance of paint in the threads, the full compliment of prep, damaged threads is possible. Not sure we can be of much more help then to explain and suggest what others have needed to do in the past. We're not in a position to see your frame.

As example do you know if your frame is Italian threaded or English (as was the trend to change to in the 1990s). Is there paint is the various threads like bottle bosses or BB shell? Are you sure that the parts you have are of the correct threading/specs? Like I said we don't know anything for real yet. Andy

this thread probably should have been posted in Mechanics or even C&V. How old is the frame? You need to find a bike shop that has an Italian bb tap(probably) and a die for the steerer. Not sure if anyone in Boise would have that.

When you write that the threads are uncooperative, it's a little vague. If they just have a little surface rust or paint you can try to wire wheel the rust or paint off. I have small one that I use occasionally that fits inside a bb shell.
If that doesn't work, then you will have to find some taps/ dies for it.

Yep, "back when" it was SOP in my shop to put each and every Italian frame-set on the flat table/fork jig to align and then mill/face/tap/ream/chase and final QC away until prepped for sale.
Find an Old School shop that still has these tools and the skills to use them or a local frame builder to perform the tasks for you.

-Bandera

See Post #5 above.

-Bandera

steel bikes usually need the bb threads to be chased in order to have reasonable threading. I don't think that is normally true of steerer threads. Unless it's just the first thread that is not that great. In either case, paint can cause this problem, but it seems like the OP would have mentioned that

The forks on most Italian frame-sets were delivered threaded and un-cut from the late 60's on, some were close to right-on the stack height of a Record HS in the early-mid 70's but w/ changing "standards" it was just another SOP job to cut forks and chase threading on each and every frame-set. No point in doing that before a build list for the customer determined what was required. Sold as a "bare" frame-set the customer got what the Mfg delivered which would generally require the work of a competent shop to do what was necessary to fit/chase the fork and install the HS of choice.

-Bandera

It really depends on the builder. Columbus sold unthreaded steerers, so it's possible that the builder of this frame did a crummy job of threading. If it is a steerer threaded by Columbus, it wouldn't need chasing at all unless damaged.

All it should take to get a steer ready is carefully filing a chamfer around the lead thread. It's normal to have a 45 degree chamfer to the root of the thread, to insure an easy start. As for the BB threads, my mid 90's Tommasini Sintesi didn't need any prep before assembly.