Based off of Canadian Highlander and Australian Highlander points lists, allowing all Middle School Era cards.

Middle School 100 Card Singleton
10 point, 100 cards

100-card MS highlander (one card maximum, except for basic lands). Same sets as MS. No sideboard (wish cards only get cards from your deck that have somehow been removed from the game during a game.) All ante cards are banned. A deck may contain a maximum of 10 points worth of cards. Points as of 2020.05.11.

ms-singleton.csv
Cards with points greater than zero:
Balance – 3
Channel – 2
Crop Rotation – 1
Diabolic Intent – 2
Eladamri’s Call – 2
Enlightened Tutor – 2
Flash – 2
Gaea’s Cradle – 1
Gamble – 2
Goblin Recruiter – 3
Grim Tutor – 2
Imperial Seal – 3
Intuition – 1
Land Tax – 1
Lim-Dul’s Vault– 1
Mana Crypt – 4
Mana Vault – 1
Merchant Scroll – 2
Mind Twist – 3
Mystical Tutor – 2
Natural Order – 3
Necropotence – 1
Personal Tutor – 2
Price of Progress – 1
Sterling Grove – 1
Strip Mine – 3
Survival of the Fittest – 3
Sylvan Tutor – 2
Tainted Pact – 2
Tinker – 3
Tolarian Academy – 1
Vampiric Tutor – 3
Worldly Tutor – 2
Yawgmoth’s Bargain – 1
Yawgmoth’s Will – 2

Middle School 60 Card Singleton
7 points, 60 cards
3 points
Imperial Seal, Vampiric Tutor

2 points
Channel, Flash, Mana Crypt, Mind Twist, Mystical Tutor, Strip Mine, Tinker, Tolarian Academy

1 point
Balance, Crop Rotation, Doomsday, Enlightened Tutor, Fastbond, Force of Will, Hermit Druid, Intuition, Lim-Dul’s Vault, Mana Vault, Merchant Scroll, Natural Order, Oath of Druids, Personal Tutor, Survival of the Fittest, Tainted Pact, Time Spiral, Wasteland, Yawgmoth’s Bargain, Yawgmoth’s Will