I just bought a Savage Mk 4 No. 1* Enfield and am cleaning it up (If anyone is missing a fence post for your hog wallow I have it). I want to get a bayonet but all I see is the Mk4 No 2 spike bayonets. Will that fit the No. 1? Thanks.
The No.4 Mk.II Spike bayonet is correct for a No.4 Mk.I or Mk.I* rifle. The "No.4Mk.II" nomenclature refers to the bayonet itself, not the rifle. The No.4 Mk.I Bayonet had a "cruciform" blade/spike, the No.4 Mk.II bayonet was developed to be cheaper and easier to make. The No.4 Mk.II and No.4 Mk.II* Bayonets are probably the most commonly encounterd spike bayonets, hence they are usually the cheapest. The difference between the No.4 Mk.II Bayonet and the N.4 Mk.II* is the Mk.II* had the spike fastened to the socket as opposed to the socket and blade/spike being one piece.
From what I have seen the No.4 Mk.I Bayonets are not too common and are somewhere in the above $100 (U.S.) price range. There are fake No.4 Mk.I Bayonets lurking about so be alert to that.
Later in the War there was a No.4 Mk.III Bayonet made that was made with (I think) stamped sheet metal for the socket. They tend to have a rather crude appearance. These are fairly easy to find, but not as easy as the No.4 Mk.II Bayonet. I hoped I helped out a bit.