I am a tad confused about these.  I have an old kit purporting to be of the MCV.  The kit has a 9' WB underframe of the 90 degree beam type.  Also two vacuum cylinders.   Here is what I got with the kit:     Yes, my copy is cut off.   Two very indistinct pictures of 8 clasp and 4 shoe examples:     This picture shows a ruined underframe with an angled arrangement of beams:  https://paulbartlett.zenfolio.com/brmineralclaspvb