The most common and most likely answer to this crossword clue is the 7 letter word GUILDER
I've seen this crossword clue in Independent
G
U
I
L
D
E
R
More clues leading to the result GUILDER
- Decorator said to make money in Europe once
- Old coin I found in rusty fruit box upended
- I show a bit of bum to make first grand
- Ready for old Dutch medic to seal demise of deceit
- After endless deceit the German was ready for the Dutch
- Former capital of the Netherlands
- Currency advice — accept fifty rupees later
Buddy explains!

The straight part
We know that "old money" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old money = guilder.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 GUILDER mean?
GUILDER noun- The former currency unit in the Netherlands, divided into 100 cents.
- The former currency unit in Suriname, divided into 100 cents.
- The current currency unit in the islands in the former Netherlands Antilles, divided into 100 cents.
- One who gilds; especially one whose occupation is to overlay things with gold.
- The former currency unit in the Netherlands, divided into 100 cents.
- The former currency unit in Suriname, divided into 100 cents.
- The current currency unit in the islands in the former Netherlands Antilles, divided into 100 cents.