Userform - Look At Offset Value Before Adding To Combobox?

I have a Userform with 2 comboboxes.

combobox1 is filled with values. I want the user to select one from combobox1 and combobox2 get filled in with unique values based on combobox1

Sheets Quote has 2 columns

Customer Job
Stanley 1
Stanley 2
Fred 1
Stanley 3
Stanley 3
Stanley 3
Stanley 4
Fred 1

combobox1 is filled in with Stanley and Fred

based on the user selection (as an example Stanley)

I want combobox2 values to be 1,2,3,4 (having 3 listed only once)

Is there a way to modify the code below to verify that the (e) .offset(-1,0).value = combobox1

Is there a different option to use?

Code:
Public Sub fill_job_num()
Dim v, e
On Error GoTo error1
With Sheets("Quotes").Range("B2:B50000")
v = .Value
End With
With CreateObject("scripting.dictionary")

[code].....