Or anyone else who might be interested. These are all for piano, violin & cello with the equivalent difficulty being about book 2 of Suzuki.
Chamber Music Sampler by Joanne Haroutounian
Pachelbel Canon arranged by Daniel Dorff. The link is actually not the same book as I got because mine is for any two or three melody instruments and piano. Violin, cello & piano would have been better but I'm just happy to have this.
Trio in D Major by J.C. Bach for violin, cello & piano. I can't find a link for this but it's published by the International Music Company and the number on the front is No. 1516.
A Christmas Tableau of Piano Trios by Eugenie Rocherolle. This contains 9 songs, including The First Noel, Silent Night and What Child is This?. It also contains a couple of more secular pieces - Jingle Bells and A Holly Jolly Christmas.
I'm looking forward to trying these out!