• ild gold,
• kld gold,
• lld gold,
• pld gold,
• 0ld gold,
• 9ld gold,
• okd gold,
• opd gold,
• ood gold,
• ols gold,
• olx gold,
• olc gold,
• olf gold,
• olr gold,
• ole gold,
• old fold,
• old vold,
• old bold,
• old hold,
• old yold

The adjective form of "old gold" would simply be "old".

The plural form of "old gold" is "old golds".

The singular form of the word "old gold" is "old gold". The term does not change in form when used in the singular.