Here are the Metallic Dragons I used for my Dragonlance campaign. I based the conversion on OD&D and AD&D MM1.
Metallic Dragons
by Antonio EleuteriBrass Dragon
Brass Dragons are found mainly in sandy desert regions.
Same stats as black dragons, except the following:
Breath weapons: Sleep 80’x30’ cone (duration 1 round per HD); Fear 50’x40’x30’ cloud (run away in fear for 1 round per HD).
Alignment: Neutral
Copper Dragon
Copper Dragons are found primarily in arid, warm rocky places.
Same stats as green dragons, except the following:
Breath weapons: Acid 60’x5’ line; Slow 50’x40’ x30’ cloud (as reverse Haste spell, duration 1 round per HD)
Alignment: Neutral
Bronze Dragon
Bronze Dragons will be found near seacoasts, and those able to talk and use magic, can appear in animal guise.
Same stats as blue dragons, except the following:
Breath weapons: Lightning 100’x5’ line; Repulsion 50’x40’x30’ cloud (move away from the dragon at maximum speed for 1 round per HD)
Alignment: Lawful
Silver Dragon
Silver Dragons abide mainly in aerial domains, i.e. mountain peaks or clouds or
behind winds. If they are able to use magic they are also able to appear in human or demihuman guise, usually taking the form of an old man or a fair damsel.
Same stats as red dragons, except the following:
Breath weapons: Cold 80’x30’ cone; Paralysing gas 50’x40’x30’ cloud (paralysis lasts for 1 round per HD).
Alignment: Lawful