Don't stress mate.  When we get a chance, bring the board over and I will replace the header pins as well as reflow anything that looks a bit sus.  Someone may be able to let you know what type of trim pot (volume) to get.  You will be able to get them from jaycar hopefully and I will change it as well.

See if you can identify what caps are on the board as well and let me know.  I have a fair few different ones here and anything I don't have you can most likely get from jaycar as well.

Only other thing really then would be replacing the connector pins.