Having made the 557 cuboid allows me to present to you my family of 55x cuboids:
55x cuboid family.jpg [ 282.84 KiB | Viewed 859 times ]
The 553 and 557 are based on the designs by OLZ, the 553 was made by Claus and the 557 was 3d (sls) printed.
The 554 was recently made by Tanner Frisby (using an Eastsheen cube) and the 556 was made last year by Tony Fisher (using a V-CUBE 666).
For the 555 I took my favourite 555 cube, the V-CUBE 555.
I hope in the future to be able to extend the family with a 255 (and possibly other types as well).