Error 1004 - object-defined error when vba code not applicable

Hi folks,

Through playing around with the macro recorder and looking at other macros, I have written the following:

Sub Fill_Gaps_Spreadsheet()

' Interrupts Automatic Calculation, ScreenUpdating and StatusBar

Application.Calculation = xlCalculationManual

Application.ScreenUpdating = False

Application.DisplayStatusBar = False

' Converts column D to number

    Range("d2:D70000").Select
    With Selection
        Selection.NumberFormat = "General"
        .Value = .Value
    End With

' Replaces current blank unit price with start of year unit price

    Range("Q2:Q70000").Select
    Selection.SpecialCells(xlCellTypeBlanks).Select
    Selection.FormulaR1C1 = "=RC[31]"


' Calculates Min Stock Value & SOH Value for current range

    Columns("R:R").Select
    Selection.SpecialCells(xlCellTypeBlanks).Select
    Selection.FormulaR1C1 = "=RC[-1]*RC[-10]"

    Range("T:T").Select
    Selection.SpecialCells(xlCellTypeBlanks).Select
    Selection.FormulaR1C1 = "=RC[-3]*RC[-9]"

' Imports old stock

    Range("AM2:AM70000").Select
    Selection.SpecialCells(xlCellTypeBlanks).Select
    Selection.FormulaR1C1 = "=INDEX(OldMinMax!R2C4:R129556C4,MATCH(RC[-38]&RC[-35],OldMinMax!R2C1:R129556C1,0))"

' Import current min where old stock is not available

    Columns("AM2:AM70000").Select
    Selection.SpecialCells(xlCellTypeFormulas, 16).Select
    Selection.FormulaR1C1 = "=RC[-31]"

' Imports current min where SOH is Nil

    Range("h2:h70000").Select
    Selection.SpecialCells(xlCellTypeBlanks).Select
    Selection.FormulaR1C1 = "=INDEX(CurrentMinMax!R2C4:R100000C4,MATCH(RC[-7]&RC[-4],CurrentMinMax!R2C1:R100000C1,0))"


' Removes index&match formula on old & current min

Dim smallrng As Range

    For Each smallrng In Range("AM2:AM70000,H2:H70000,Q2:Q70000,R2:R70000,T2:T70000").Areas

        With smallrng
            .Cells.Copy
            .Cells.PasteSpecial xlPasteValues
            .Cells(1).Select
        End With
        Application.CutCopyMode = False

Next smallrng


' Restores Automatic Calculation, ScreenUpdating and StatusBar

Application.Calculation = xlCalculationAutomatic

Application.ScreenUpdating = True

Application.DisplayStatusBar = True

End Sub

My only issue is that if one of the elements of the macro does not apply (eg there are no blank cells in R:R), I have an error and the macro does not run.

Can someone please tell me what to add to bypass this problem and allow the macro to continue running? Also, if any of you can see a way to speed up the processing of the macro (which takes quite a bit of time at the moment), I'll be very grateful :-)

Thanks in advance.
S