Why "Sheila Caffell" and "J Bamber"? As far as I know that could as well mean JUNE Bamber as JEREMY Bamber. Why just "J"?
Please read attached statement by Detective Inspector, Ronald Walter Cook. (Can be found in full in the "Documents in the melting pot" thread.

The form is signed 'J. Bamber' by Jeremy to confirm that the finger prints on the form belonged to him.
June had been murdered and was therefore unable to sign her name.

It's not sloppy work, it's an accurate description of a document, it cannot be described as being Signed Jeremy Bamber because it is signed J. Bamber.