95% to be precise. These were the retail rates. EuroAion states rates are retail, so it should work like it here as well. However L105 are expensive, supplements too, prepare for a big kinah sink. Finding good source for old content is very hard nowadays, I found this: http://webcache.googleusercontent.com/search?q=cache:uN0rUpsUHEQJ:www.mmowa.com/news/a/game_news/game_news_1598.html+&cd=5&hl=en&ct=clnk&gl=hu
Chance of Enchanting
Level Difference
Heroic
Fabled
Eternal
Mythic
0
40%
20%
0%
0%
5
50%
30%
10%
0%
10
60%
40%
20%
0%
15
70%
50%
30%
10%
20
80%
60%
40%
20%
25
80%
70%
50%
30%
30
80%
80%
60%
40%
35
80%
80%
70%
50%
40
80%
80%
80%
60%
Using Supplements
Supplement Type:
Increased Chance by:
Lesser Supplements
5%
Normal Supplements
10%
Greater Supplements
15%
This source does not confirm the rates for mythic, but I will find a reliable source for that one as well. This only tests till +40 difference, but 4.6 has higher level stones too!