This is probably not much help I very much doubt this Butler is a "Massed Start Model". The 1940's lugless models that were commonly fitted with CB Continental ends were, Close Circuit Model No.7. International Club, Brevit No.11 and Miss Modern. These lugless Clauds from this period are notoriously difficult to identify. Seat clusters (wrap-overs) and frame angles are sometimes the only way.
Best wishes and be lucky. Michael Butler Huntingdon UK.
>From: ralph03@optonline.net
>To: classicrendezvous@bikelist.org
>Subject: [CR]1940's Claud Butler
>Date: Sat, 24 Jan 2004 21:35:12 -0500
>
>Hello, I am new to this site and have a question about a 1940's Claud
>Butler Frame set. It is a Luggless 22" frame, with Continental Dropouts. It
>has original Finish with Creamy yellow paintwork, red wrapping where the
>transfers are. Frame No. is 171470. I was told it may be the MASS START
>model. It is exceptionally light, & is defiantly not your normal 531
>lightweight (frame 4.1 pounds, fork 1.7 pounds). See pictures on Ebay item
>number 2212225234. I would really appreciate it if some one can provide me
>with specifics on this bike.
>
>rgds,
>Ralph