Are there any particular numbers an end consumer/user like me should look out for? Obviously a lamp or bulb can be bad regardless of which number is after the "E" mark because the regulations themselves allow too much variance, but assuming the type approval is legit, is a lamp or bulb with a say, "E1" mark more likely to have been vetted than a lamp or bulb with an "E11" or "E13" or "E24" mark?
Certification of Economic Commission for Europe (referred to as ECE, United Nations agency), the E-Mark: E-Mark is the regulations issued by the Economic Commission for Europe (referred to as ECE). E-Mark logo is a circular frame. The number is the EU country or state number that granted approval. If one state grants approval then it is deemed sufficient for all other member states. The country/state codes are as follows: E1 – Germany, E2 – France, E3 – Italy, E4 – Netherlands, E5 – Sweden, E6 – Belgium, E7 – Hungary, E8 – Czech Republic, E9 – Spain, E10 – Yugoslavia, E11 – United Kingdom, E12 – Austria, E13 – Luxembourg, E14 – Switzerland, E16 – Norway, E17 – Finland, E18 – Denmark, E19 – Romania, E20 – Poland, E21 – Portugal, E22 – Russian Federation, E23 – Greece, E24 – Ireland, E25 – Croatia, E26 – Slovenia, E27 – Slovakia, E28 – Belarus, E29 – Estonia, E31 – Bosnia and Herzegovina, E32 – Latvia, E34 – Bulgaria, E37 – Turkey, E40 – Macedonia, E42 – European Community, E43 – Japan, E45 – Australia, E46 – Ukraine, E47 – South Africa.
Simple answer is to probably buy from know manufacturers to avoid fake units. The E1 code refers to Germany so the likes of Hella or Bosch etc will be a safe bet.