The most common and most likely answer to this crossword clue is the 4 plus 1 plus 4 letter word BRIC A BRAC
I've seen this crossword clue in The Daily Telegraph
B
R
I
C
A
B
R
A
C
Buddy explains!
The straight part
We know that "Old curiosities" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old curiosities = bric a brac.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BRIC A BRAC mean?
BRIC A BRAC noun- Small ornaments and other miscellaneous items of little value.