I remember Ysgarth from my role playing days in the late 1970s. The game first was published in 1979. It was one of a number of fantasy rpgs that I remember we tried before finally settling on the Warhammer Fantasy Role Play.
Ysgarth has got a pretty complex system of skills and attributes, but action is resolved on a simple d100 (that is, you roll 2d10s and read them as separate decimals)
Searchers of the Unknown is a set of free role playing rules. These are one-page, minimalist rules, each of which is designed as a stand-alone product. The collection includes: Searchers of the Unkown, Dwarven Glory (and supplement), Karry on Krawling, Witches of N’kai, Adventurers!, Cyborg Samurai Are Go!, Dirty Rotten Scoundrels, Funkin Fists of Fu, Jung Guns, Raiders of the Unknown, The Bastards, Brickmasters of the Unknown, Mutant Got Gunz, Mutant Scavengers of the Ruined Earth (and supplement), Tempora Mutantur (and supplements), Searchers in Spaaaace!!!, Scavengers & Spacewrecks, Swashbucklers of Mars (and a supplement), and Song of the Symbi.