The single W corrections are two multiplicative factors, one of which
refers to alpha running at the t scale and the other to photon radiation
in the t channel. These corrections are ALWAYS calculated for any
single W event, and are available respectively in kwgt(62) and (63).

Events can be generated with the corrections applied to events for which
the electron is within a ceratin angular cone (this is what the authors
recommend, however the tuning of this angle is to be done... by us).
The weights which have actually been aplied to each event are kept
in kwgt(60) and (61).

Events will normally be generated with NO correction for single W events.
This means that normally you will find kwgt(60)=kwgt(61)=1.

In general, you can obtain:

Reweight to singleW events with NO correction.
=> multiply by 1/kwgt(60) * 1/kwgt(61)

Reweight to singleW events with correction for all angles
=> multiply by kwgt(62)/kwgt(60) * kwgt(63)/kwgt(61)

Reweight to singleW events with the correction switched on for some angles
=> if (... electron is within the desired cone ...) then
      multiply by kwgt(62)/kwgt(60) * kwgt(63)/kwgt(61)
   else
      multiply by 1/kwgt(60) * 1/kwgt(61)
   endif

Notice that you generally will NOT need to multiply by
1/kwgt(60) * 1/kwgt(61), I am just adding this year for your
information... In any case it does not harm as they are =1!