Thinking about ordering a C-Flat custom tamper, I measured three La Marzocco double baskets with spring ridges and one La Marzocco triple basket for the naked portafilter. Also, measured was two double baskets for the Iberital - both with no ridge. The measurements are as follows;

La Marzocco,above the ridge.
#1 double basket - 58.5 mm
#2 double basket - 58.7 mm
#3 double basket - 59 mm

La Marzocco triple basket straight sides - 59 mm top to bottom.

Iberital - straight sides, no ridge
#1 double basket - 58.2 mm
#2 double basket - 57.5 mm

I have the Iberital in storage and only trying to fit a C-Flat tamper to the ridged LM portafilter baskets and I am at a loss of what size to order. I know it will only fit one of the baskets well, one other partly, and will not work well with the third. I just wonder why the espresso machine companies make beautiful exteriors and perfect mechanical fittings, but can't press baskets that are round and within a reasonable tolerance?