Добавить в _g.script на строку 905:

function IsTrader(o,c)
    if not (c) then
        c = o and o:clsid()
    end
    return c and (c == clsid.script_trader) or false
end

И заменить два метода в ranks.script с 58-91 строки на:
function get_obj_rank_name( obj )
    if not ranks_loaded then
        read_all_ranks()
    end

    local obj_rank = obj.character_rank and obj:character_rank() or obj.rank and obj:rank()
    if not (obj_rank) then
        return ""
    end

    local cls = obj:clsid()
    if IsStalker(nil,cls) or IsTrader(nil,cls) then
        return get_rank_name( obj_rank, stalker_rank_intervals ) or stalker_max_rank_name
    else
        return get_rank_name( obj_rank, monster_rank_intervals ) or monster_max_rank_name
    end
end

function get_se_obj_rank_name( obj )
    if not ranks_loaded then
        read_all_ranks()
    end

    local obj_rank = obj:rank()
    local cls = obj:clsid()
    if IsStalker(nil,cls) or IsTrader(nil,cls) then
        return get_rank_name( obj_rank, stalker_rank_intervals ) or stalker_max_rank_name
    else
        return get_rank_name( obj_rank, monster_rank_intervals ) or monster_max_rank_name
    end
end

И станет Сидор легендой :D