nested IF formulas - need to resolve inconsistent error! (quick help needed if possible)

Ok... Here is what I've got:
=IF(LEFT(D260)="O","Overhead",
IF(AND(Sheet2!B8LEFT(D260)="E"),"Equipment",
IF(LEFT(D260)="C","Crews",IF(LEFT(D260)="A","Aircraft",
IF(LEFT(D260)="S","Supplies",
IF(ISNUMBER(SEARCH("E-",D260)),"Personnel", ""))))))

The last if is a discrepancy in the report I pull from the database. I need any E*-*.* (any cell with text that begins with E and has a "." as part of its text string) to Show as Overhead as well.

I understand why it is inconsistent, but with limited Excel background and time crunch, I'm reaching out for help.

I need something to say If [begins with E and does not contain ".", then "Equipment"] BUT if [beings with E and contains "." as part of text string, then "Overhead"].... along with all of the other IF statements of course.

THANKS!!! in advance.

=IF(AND(LEFT(D260,1)="E",NOT(ISERROR(FIND(".",D260)))),"Overhead",IF(LEFT(D260,1)="O","Overhead",IF(LEFT(D260,2)="E-","Personell",IF(LEFT(D260,1)="C","Crews",IF(LEFT(D260,1)="A","Aircraft",IF(LEFT(D260,1)="S","Supplies",IF(LEFT(D260,1)="E","Equipment", "")))))))