From my Samples, Singulars, and Somethings Completely Different collection -

16th century breastplate, backplate, fauld, and tassets. Mild steel, armorer unknown. Probably made for jousting - the main breastplate is thicker than the other elements - spot measurements vary from 2.75 mm (top of breastplate) to 1.75mm (tassets and back), with many areas measuring 2mm (curse you, cheap micrometer!)

Roughly sized: will fit an xl to xxl sized fighter.

breastplate:
center line 16 3/4" (neck to bottom)
center line 18" including faulds
width across top with side plates extended: 10 1/2"
width at widest 25 1/2" (top of arm cutouts)
width of curve following waistline: 27"
width across bottom of longest fauld: 30 1/2"
9 lb 11.5 oz

backplate:
top to bottom 18 1/4"
widest part: 124"
waist curve: 19 1/2" (roped border to roped border)
5 lb 8.5 oz

tassets:
11 1/2" long
top of each lame:
13 1/2", 12 1/4", 12"
2 lb 8.0 oz /each