Hi !I did a custom desgin for the 121 vcf and 150 ringmod.i did the design spacing between knobs and so is as on the original curetronic design.if you are interested i can send some photos -- Oliver, DL6KBG, JO61UBOnline-SDR: http://dl6kbg.dyndns.orgBlog: dl6kbg.blogspot.com