If made mid-1924 or later, it will be the long base. Lyman specifically mentions "for rifles after serial number 260000" on period blister packs. The heights of the blades varied to match cartridge classes (303/30WCF and 250/300 Sav).
Lyman had #26 and #32 front sights.
Redfield and Marbles (#16?) also had sights.
The sight is 0.0625" thick, IIRC. Krag and Springfield '03 commercial sights can work regarding thickness, but are frequently too tall. Shorten the top of the blade, you lose the "bead". Shorten the bottom of the blade, you lose the retaining pin hole. I have one rifle with a '03 Springfield front sight, and scars on my right hand to prove it. It is too long for the base, sharp, and needs a little file work, but the retaining pin hole is in the right config. I like thin "post" style front sight over a bead, anyway.
A friend spent a few minutes with a mill file, bench vice and drill press to convert half a real copper US penny to work. Abe watches over the action, to boot! Chuck it up in a piece of thin leather, remove edge and flatten, cut, and drill hole. You could use later zinc pennies, but they aren't as easy to work.
Source is Google and eBay. Loose sights at gunshows can be found, but it is hard to tell if used for Savage 99, Krag, Mann., or Spfld.: figure out the height and length you need, then measure the sight before buying.
