"Archer Skeleton" would probably work (could be cross-listed as "Skeleton, Archer"). Unless there are other "Archer Skeletons," I wouldn't feel the need to put "Ravenloft" or "Karakin" into the name.
Well I'll be Indexing both Archer Skeleton and Skeleton, Archer when I actually add them to the Creature Catalog. It's just a question of which you prefer as the name on the monster entry.
As for other Archer Skeletons, there are a couple in 3E: The Barrow of the Forgotten King has Skeletal Archers (which are just standard SRD Human Warrior Skeletons armed with shortbows and +1 flaming arrows) and Dragon #317 has the Eldritch Archer (a new monster based on the D&D Heroes video game. It's an animated skeleton of an elven arcane archer with 16 HD and a +5 keen composite longbow.)
Let's deal with the easy stuff first. All the red text down to the full attack line is fine.
Fine by me.
I guess the original monster's "damage resistance" turns into the DR 5/bludgeoning of the 3.5e skeleton.
That's what I'd go for.
The original also has "spell immunity." Does that just convert to immunity to cold and other undead immunities, or should we add some SR?
It's the standard AD&D undead trait plus the common skeleton's immunity to cold:
From Ravenloft Monstrous Compendium Appendix III: Creatures of Darkness (1994)
Archer skeletons are immune to sleep, hold, charm, or fear spells. They need never check morale, usually being magically commanded to fight to their destruction. They are also immune to all cold-based attacks, as are normal skeletons. Similarly, edged and piercing weapons do only half damage to these creatures, while blunt weapons, being designed to crush bone, do full damage.
Environment and org lines are good, and I'd probably go with - for advancement.
I'll go along with that.
Updating Archer Skeleton Working Draft.
If that's all good with you, shall we tackle the bone arrows?