Understanding Society User Support

I would like to ask about the components used for deriving income variables. For example, in BHPS, individual pension income (wFIMNP) is constructed by ‘summing the amount received, converted to a monthly basis, for all wINCOME Records where the wFICODE takes the values 2, 3 or 4, and where the amount is currently being received’. However, in UKHLS the definition changed, pension income (w_fimnpen_dv) includes ‘receipts reported in the income data file where w_ficode equals [2] “a pension from a previous employer”, or [3] “a pension from a spouse’s previous employer”.’ I want to create a consistent pension income measure that include income receipt from sources where wFICODE takes the values 2, 3 or 4, but I don’t know which variable in the _income datafiles represent the amount received that is used to derive these variables. For example, in UKHLS, adding values from the w_frval column where wficode is 2 or 3 does not always equal to the derived value of w_fimnpen_dv (similarly in BHPS, adding w_frval column where wficode is 2, 3 or 4 does not always equal to the derived value of w_fimnp).

I suppose in UKHLS, instead of w_frval, w_frmnthimp_dv for each income source is used to calculate the total income of a category, but is there an equivalent of w_frmnthimp_dv for BHPS? Thank you!