Your Rover 25 would have originally been fitted with an electronic ignition type (non-distributor) K series.
The distributor is for the ignition system and is nothing to do with the fuel which is as you say an electronic fuel injection system. The protruding shaft is for the distributor and dates the engine to before 1999 and may be from either a Rover 'bubble' 200 or 400 or an MGF. The engines made from 1999 onwards and fitted to the 25 and 45 (and later to the ZR and ZS), late MGF and TF had electronic ignition via two coilpacks mounted on top of the spark plugs for cylinder one and cylinder three. It was thus what is referred to as a 'wasted spark' system as two cylinders recieve a spark at the same time, but one is on its induction/compression stroke, and the other on its power/exhaust stroke so only one fires and so one spark is 'wasted'.
The number cast onto the camshafts is the part number for the cast blanks as they were recieved from Federal-Mogul. They were then machined at Longbridge. The only way to know what they are is to measure the valve 'lift'.
The factory fit cam sprockets were always manufactured by GKN.
I would guess it is probably either just a pre-1999 distributor ignition engine from an earlier car which has been transplanted and fitted with the later cam carrier (to accomodate the coil pack arrangement) or it is a later 'wasted spark' type engine which has had the cylinder head replaced with one from an earlier car - either way it is not ideal as the cylinde head and camshaft carrier were machined as one piece (ie. clamped together) so fitting a cam carrier that is off a different means that the cam journal may not be a perfect match, which may lead to premature wear.
Good luck with the Lada conversion (I am surprised there are any Ladas left, as most of the decent ones used to get bought up by Russian sailors whose ships put in to UK ports, and the cars were taken back to Russia (the UK importer used to dismantle the new cars and rebuild and respray them before sale to UK customers, so they were actually better built than those sold in Russia, and therefore commanded a significant price premium when returned home).
The distributor is for the ignition system and is nothing to do with the fuel which is as you say an electronic fuel injection system. The protruding shaft is for the distributor and dates the engine to before 1999 and may be from either a Rover 'bubble' 200 or 400 or an MGF. The engines made from 1999 onwards and fitted to the 25 and 45 (and later to the ZR and ZS), late MGF and TF had electronic ignition via two coilpacks mounted on top of the spark plugs for cylinder one and cylinder three. It was thus what is referred to as a 'wasted spark' system as two cylinders recieve a spark at the same time, but one is on its induction/compression stroke, and the other on its power/exhaust stroke so only one fires and so one spark is 'wasted'.
The number cast onto the camshafts is the part number for the cast blanks as they were recieved from Federal-Mogul. They were then machined at Longbridge. The only way to know what they are is to measure the valve 'lift'.
The factory fit cam sprockets were always manufactured by GKN.
I would guess it is probably either just a pre-1999 distributor ignition engine from an earlier car which has been transplanted and fitted with the later cam carrier (to accomodate the coil pack arrangement) or it is a later 'wasted spark' type engine which has had the cylinder head replaced with one from an earlier car - either way it is not ideal as the cylinde head and camshaft carrier were machined as one piece (ie. clamped together) so fitting a cam carrier that is off a different means that the cam journal may not be a perfect match, which may lead to premature wear.
Good luck with the Lada conversion (I am surprised there are any Ladas left, as most of the decent ones used to get bought up by Russian sailors whose ships put in to UK ports, and the cars were taken back to Russia (the UK importer used to dismantle the new cars and rebuild and respray them before sale to UK customers, so they were actually better built than those sold in Russia, and therefore commanded a significant price premium when returned home).