Tweaking the game

[ripforareason]

I'm interested in tweaking the game a little bit, in particular, adjusting some artefact rarities, maybe removing Creeping Horrors, and maybe adding an item or two. Basically, I'm trying to get a slightly different distribution of artefacts so that the same ones don't show up every game - the usual suspects are Fingon, Kiteshield of Hador, Glamdring, Belthronding, Maedhros, Gamil Zirak, Taur-nu-Fuin. Fingon in particular is very good and seems to spawn at least every other game, but its rarity is pretty high and comparable to some artefacts that I've never seen playing Sil. edit: apparently it spawned in 2/3 of my winning games, wow.

Do I need to do anything other than edit artefact.txt, monster.txt, and the like?