I am no mechanic nor have I ever laced a wheel. I did a little racing back in the day and I have a memory of what I would call "common knowledge" regarding equipment at least with the guys I rode with. This is the mid to late 70's which I think was the time frame the person who started the thread was concerned with.
We used the high flange for crits and even short road races with lots of turns. Low flange were for medium to long road races.
The "common knowledge" was that the high flange gave you more strength in turns and a "harder" feel to crisply carve a turn. The low flange was for a "smooth, softer" feel for long races. My 2 cents.
I suppose for a period correct restore, if you've got both you should go with what looks the best.
James Doolittle
Spring, Texas, USA