Oldies...
I spent a lot of years some time back, haunting Ebay for old classic Lyman, Marbles, King, and some other vintage sights. I am not aware of anyone
currently making such a sight for the original military Springfield sight base.
However, Lyman and possibly others did. They also made a Sheard front sight, which is a somewhat similar design to a bead sight. If you don't have it, I recommend you get Nick Stroebel's classic book on vintage gunsights.
He wrote one on vintage scopes and mounts, also.
I would NOT recommend you get the later edition that attempted to combine both into one volume. Very poorly done with a lot of information omitted that was in the earlier editions. I gave my early "Gunsights" book to a friend when the later "combo" version came out, and once I saw how poorly it was done, I hunted down an early version of the Sights book and
paid more for it used than I had new.
The book will tell you the nomenclature of the sight(s) you're looking for,
let you know what was available from a number of classic makers, and will
greatly improve your Ebay search results. I hope this helps!
John