I would like to suggest a few improvements to the Attachments tab.
I guess the date shown is the date the attachment was imported. while this is useful, in my opinion the date of the actual transaction to which it is attached would be more useful for users. it is difficult to search for the transaction without knowing the actual date. so can this be added as a column and set as the default for sorting the list?
for the same reason above, it would help if the Reference of the actual transaction was added as a column. this would help when there are more than one transaction of the same type on the same day from the same party. if the reference could act as an hyperlink to the transaction it would be even better.
when you click Edit, it would be helpful if there was an option to browse for a different file to be attached in case the user wants to replace the existing attachment.