1 Pure gold's extracted from exceptionally ill-used old gun (9) – Unsullied? (Anagram of “ill used old gun” with “gold” removed.
2. Identical caps taken in disorder (4-4) Beri-Beri? (Twins caps i.e. hats “beret beret”)
3. Stoppers used to keep the last of water in drums (5)- Less sure- thought Traps (taps (drums+ r)
4. Leg additionally presented at Christmas time? (8,6) - Stocking filler? (Leg as stocking filler – given as additional gift at Xmas)
5. Mark in soon with ink stylograph. Messiness leads to friction (10) Antagonism? (Mark (tag) in anon (soon) with “leads” of “ink stylograph. Messiness” – ism)