Typical dimensions of late Gothic composite bows

Hi guys, my long term project has reached the point where I am ready to build a composite prod. There is too much info out there (ironically) so I need to narrow things down. Any idea on the typical dimensions of a sporting crossbow composite prod of the late 15th century Germanic/saxon/tyroll region, otherwise known as a late Gothic style? Particularly, the thickness at centre??
Thanks in advance
Andrew