Yes, the method you describe is the way to go. However, if you try to skip going to 1.07 first with set or unique items you will get some buggy results with a lot of items (Unique War Staff for instance). Level requirement of rares I am not sure...
And no, you cannot socket items pre 1.09. But you can bring it forward with a 1.00-1.06 SoJ and socket it there.
Here are some of my bugged items in my GoMule stash. Again, these are legitimately found and brought forward with no 3rd party software involved. Note that the result is the same every time.
Code:
The Iron Jang Bong
War Staff
Two Hand Damage: 24 - 56
Durability: 243 of 250
Required Level: 28
Fingerprint: 0x3097d746
Item Level: 80
Version: Legacy (pre 1.08)
+2 to Paladin Skill Levels
+20% Faster Cast Rate
100% Enhanced Damage
50% Bonus to Attack Rating
+2 to Nova (Sorceress Only)
+2 to Blaze (Sorceress Only)
+3 to Frost Nova (Sorceress Only)
+30 Defense
Steelclash
Kite Shield
Defense: 54
Chance to Block: 33
Durability: 166 of 168
Required Level: 17
Required Strength: 47
Fingerprint: 0x1b4d4ade
Item Level: 82
Version: Legacy (pre 1.08)
+1 to Sorceress Skill Levels
+20% Faster Block Rate
25% Increased Chance of Blocking
+82% Enhanced Defense
+20 Defense
All Resistances +15
Damage Reduced by 3
+3 to Light Radius
+18 Maximum Durability
Being level 1 requirement you pretty much one shot everything up to a good part of the game, especially with two SoJ's that add lightning damage as well and blood fists.
I also have a 275 page long document written in 2001 about Diablo 2 classic patches. It has some useful stuff.
Just remembered also another instance with bugging items. If you transfer a Gull from 1.00 (50% MF) directly to 1.13d it will get 100% MF. But by going to 1.07 first then 1.13d it will be 50% MF. So it can be exploited in a lot of ways.
You can also bring forward rare exceptional weapons to essentially re-roll them in later patches in classic if they are terrible items in 1.00-1.06. Also, set items becomes super bugged and you can have some pretty creative set combinations as the set bonuses remain even though the base changes.
Here are some of my items on my Sorceress that have been all obtained in 1.00. It's pretty crazy..
Code:
Beast Veil
Cap
Defense: 3
Durability: 11 of 12
Required Level: 41
Fingerprint: 0x27c94467
Item Level: 58
Version: Legacy (pre 1.08)
+20% Faster Hit Recovery
+11 to Dexterity
+97 to Life
Cold Resist +21%
Lightning Resist +43%
Fire Resist +26%
1 Sockets (1 used)
Socketed: Perfect Ruby
Hailstone Jack
Quilted Armor
Defense: 8
Durability: 18 of 20
Required Level: 41
Required Strength: 12
Fingerprint: 0x1c4f6c72
Item Level: 58
Version: Legacy (pre 1.08)
+20% Faster Hit Recovery
+13 to Dexterity
+51 to Life
Cold Resist +25%
Lightning Resist +49%
Fire Resist +27%
Dire Chain
Sash
Defense: 2
Durability: 11 of 12
Required Level: 41
Fingerprint: 0x6413675e
Item Level: 43
Version: Legacy (pre 1.08)
+17 to Strength
+4 to Dexterity
+56 to Life
Cold Resist +26%
Lightning Resist +16%
Fire Resist +24%
Raven Spur
Boots
Defense: 2
Durability: 12 of 12
Required Level: 1
Fingerprint: 0x44275c77
Item Level: 28
Version: Legacy (pre 1.08)
+30% Faster Run/Walk
+20% Faster Hit Recovery
+18 to Strength
Cold Resist +40%
Lightning Resist +43%
Fire Resist +31%
And these are just on my Sorceress. I have many more and even better items too just from gambling in 1.00.