The Wighton Database is a pretty comprehensive index of all the books in the collection, most of them with complete lists of the titles of tunes in the books.
The old database is broken. There are plans to place it on Dundee Council servers and to expand it, but this work has not been completed yet.
In the meantime you can use this temporary online searchable version of the database made and hosted by John Bagnall. John has also designed some queries which will output pdf-files :
Complete Wighton Catalogue (451 pages)
Wighton list of Imprints (135 pages)
Wighton Title Index (109 pages)
Wighton Short Title List (108 pages)