Observed serial data would suggest 1918 production with no prefix would include Enfield, SSA and Lithgow (but as you point out higher numbers, the changeover to MkIII* happened some time after 97442 according to the observed data)
The standard bayonet for the SMLE No 1 MK III and the SMLE No 1 Mk III* rifle was the Pattern 1907 Bayonet. Every SMLE rifle produced had a bayonet with a matching serial number issued with it. However, for a variety of circumstances, most Pattern 07 bayonets and SMLE rifles ended up being mismatched during the service life of the rifles and bayonets.
Note: Many SMLE rifles that survived the First World War were refurbished by British and Australian small arms factories. Refurbished SMLE rifles have had their original serial numbers struck out on the knox form (where the serial number is located on the front of the receiver- normally the right hand side) and a new one added to replace the struck off serial number, usually underneath the struck off serial number. 2b1af7f3a8