I have already made and presented a table in the style of the 1e AD&D DMG which incorporates the Melee Combat Tables into the Weapon versus Armour Table. You can view that pdf here. It relies on a quite widely known property that the Combat Tables are completely linear and reducible to a simple concept such as THAC0. Determine the attackers Fighting Rank using the table below and you are ready to go. In my campaign there are Fighters, Magic-Users and Other, the Assassin standing on the FR table for Other.
|note: My 'Armour Class' is 21 - AC|
AD&D combat is fine initially for several levels until it becomes apparent that linearity keeps higher level fights tediously similar and Hit Point inflation extends fight duration.
To keep fights brief, and so feel dangerous, I decided that adversaries cancel Hit Points beyond their base level, that is HPs bestowed abstractly as a measure of luck, fate and experience cancel. Base HPs for Fighter 7, MU 3, Other 5, and add CON bonus. Monster 7 + 2xHD. For example, 5th lvl Fighter with 17 CON has 43 HPs - his Base HPs: 10. For example, Ogre Base HPs - 15. Let us say these two meet to fight. Fighter currently at 22 HPs, the Ogre currently at 24 HPs. Reduce HPs of both until one reaches his Base HPs. So the fight begins with Fighter HPs 13 - Ogre HPs 15. When the fight is over the Fighter if he survives recovers the abstract 9 HPs which were cancelled.
The second decision I made is to reduce the types of armour to three kinds: PLATE, CHAIN & LEATHER. With this simplification I can add some complexity by varying the damage done by a weapon against each armour type. I have also made PLATE much harder to penetrate, of course it is rarer than presented in the AD&D books and proportionally more expensive (I use my own prices for items on a silver standard).