I suspect it might be a bit too big for the only obvious place for it to go.... I'm looking at fob watches on Amazon to see if there's anything that might suit.
The Chronos is 55mm diameter. http://www.ebay.co.uk/itm/Dashboard-Clock-for-Classic-Car-Black-Face-55mm-Diameter-/151737765397?hash=item2354468e15:m:mAksNmokoq40bU1Xj0nb-xw
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4
Using the idea of a cheapo watch and velcro from others I had a go myself. All of £7.99 from the internet http://www.ebay.co.uk/itm/INFANTRY-INFILTRATOR-Mens-Quartz-Wrist-Watch-Sport-Military-Tactical-Army-Black-/181934724988?hash=item2a5c27977c:g:1I0AAOSwLzdWSaXz please excuse the name, but the watch is almost clock sized. The horns were then sawn off, I toyed briefly with the idea of using the ‘holes’ in the case to mount it but opted to use velcro, one of the switches and its location. All pretty self explanatory.
Suitably ‘Blue Peter’-ish but no dash boards or wallets here harmed.