OSR Thief: Revised Labyrinth Lord Class

I plan on running a Dolmenwood hexcrawl campaign eventually, so I've been looking over a variety of OSR systems to use as a chassis to bolt house rules onto. I've always liked Labyrinth Lord and my players tend to like AD&D, so here I am tinkering on classes.

I plan on having the players use the core human classes (cleric, fighter, magic-user, and thief) and a non-magical explorer/ranger class. I want to give them a few extra abilities, and tweak them a bit.

THIEF

Requirements: None

Prime Requisite: DEX

Hit Dice: 1D6

Saving Throws: Same As LL Thief, but see class abilities for a bonus vs. traps.

Thieves have a THAC0 as per the standard LL rules.

A thief usually belongs to a Thieves Guild from the character's local town, where they can seek protection, shelter, and information between adventures as long as they pay their dues... Thieves cannot wear armor heavier than leather, and they cannot use shields (but their AC improves at levels 4, 7, and 9). They can use any weapon. A thief can backstab if they can roll a successful move silently and hide in shadows skill. This grants them a +4 to hit and will multiply all damage by 2 (but this increases at higher levels). They get a bonus to saving throws vs. traps at 2nd and 5th level. Finally, Thieves at 3rd and 8th level can reduce their falling damage by the amount in feet shown if they can use a nearby wall to slow themselves.

Note that there are a few new thief skills below and that their percentages are higher than the core LL ones.

XP	Lvl	HD	Abilities
0	1	6 HP	Backstab, Thief Skills
1,251	2	2D6	Save vs. Traps: +3
2,501	3	3D6	Slowfall: 30'
5,001	4	4D6	AC: 1 Better
10,001	5	5D6	Save vs. Traps: +6
20,001	6	6D6	Backstab: x3 Dmg.
40,001	7	7D6	AC: 1 Better
80,001	8	8D6	Slowfall: 60'
160,001	9	9D6	AC: 1 Better
280,001	10	10D6	Backstab: x4 Dmg.

Thief Skill	Lvl 1	Lvl 2	Lvl 3	Lvl 4	Lvl 5	Lvl 6	Lvl 7	Lvl 8	Lvl 9	Lvl 10
Climb Walls	90	91	92	93	94	95	96	97	98	99
Escape Bonds	35	44	52	60	67	74	80	85	89	92
Find and Remove Traps	41	50	58	66	73	80	86	91	95	98
Find Secret Doors	1-2	1-2	1-3	1-3	1-3	1-4	1-4	1-4	1-5	1-5
Forgery	39	48	56	64	71	78	84	89	93	96
Hear Noise	1-2	1-2	1-3	1-3	1-3	1-4	1-4	1-4	1-5	1-5
Hide in Shadows	33	42	50	58	65	72	78	83	87	90
Pick Lock	43	52	60	68	75	82	88	92	96	99
Pick Pockets	45	54	62	70	77	84	90	93	97	99
Move Silently	60	65	70	75	80	85	90	94	97	99