It's highly unlikely that you would be able to change any pre-Euro currency outside the country concerned. In the country concerned you may be able to change it at their national bank, but you may be too late even there.
Next time you travel, put the money in one of the charity collection urns which you will find in many airports.
Failing this, maybe an Oxfam shop would take it.
In Ireland, the Central Bank of Ireland (across the road from Trinity College) will still change your old punts for EURO and they haven't said that will ever stop doing this. Apparntly, one farmer arrived up with a big box and said to the cashier "count that, I think you'll find there's IR�40K in it" The cashier counted it and replied "sorry sir, there's only IR�30K here" the farmer swore and said "I must have brought the wrong box"