Ron Kitching catalogued them as handlebar rests in the 50s in chrome plated steel, brand named "Record"; they were French imports. In the 1980s, he sold them in plastic under the name of '"Arresta" Handlebar Rests'. I use two of the plastic ones, which tend to split when tightened. I don't know of anyone manufacturing them now, but they occasionally turn up on ebay.
Neil Foddering Weymouth, Dorset, England
> From: G.J.Taylor@bath.ac.uk
> To: classicrendezvous@bikelist.org
> Date: Wed, 14 Apr 2010 15:26:59 +0100
> Subject: [CR] Hand rest for vintage fixed gear project
>
> Dear All,
>
> I am new to the list so hope the following is not out of scope. I would
> ask, in advance, for your patience if this is a particularly ignorant
> question.
>
> I am looking for a bike part but don't know what it is called so I am
> finding it difficult to look for! I therefore hope you will not mind if I
> call upon your collective wisdom!
>
> Back when all roadies rode a fixed wheel bikes would only have a front brake
> (the same is true today of fixies). I have a number of old photo's (1950ish
> I think)where the other brake lever is replaced by a sort of a metal stump
> that attached to the handlbars and enables the rider to rest their hand on
> it.
>
> I would really like to get hold of one of these for an old Holdsworth
> roadpath bike that I am putting together. Does anyone have any idea what
> they were called and ideally where I might get one?
>
> Many thanks,
>
> Gordon Taylor, Somerset, England