Success! Many thanks to everyone on here for your help. I have now fitted the 4750XL to my Como 4, it took 2 mins. My Como is new and is fitted with mounting lugs for a cafe lock, hole spacing 108mm (no need for a mounting kit). As such it can accommodate either the 4750X or the 4750XL which is the same lock with a wider cutout giving a greater clearance for the tyre and is a more comfortable fit (my preference)t. I understand the Vado with a narrower spacing can only use the 4750X as the bigger cutout on the XL restricts the length of the mounting slots. I used the inner slots as these also give a better clearance.
I added the adapter cable (18243 3) for added security, this is a simple plug in. I am planning to get an Ivytex chain, but have only located the standard chain here in the UK. The Ivytex sheath costs about £5 extra and supposedly adds some angle grinder resistance by melting and clogging the abrasive surface.