I've seen several threads regarding the widths (15mm for arms, 20mm front legs, 25 back of legs, etc.).  I'm trying to build to Centurion requirements.  My question is if the cover strip needs to cover the entire flat joint area.  In other words, if the flat joint area measures 25 mm, does my cover strip then need to be 25mm or can I use the 15mm to be accurate?