[DCRM-L] Signature practice with odd leaf number

[Ken Rockwell]

Well, here I go displaying my inexperience...  It'll take some time to get all the variants in signature statements down, so thought I'd try a little public embarrassment and throw out this "odd" one:

I have a book with 5 preliminary leaves (roman numeral x on last), an unsigned gathering of 8, then the signatures kick in with numeral 2 through 16 in eights; gathering 17 has 5 leaves, and gathering 18 (with heading "Supplement") has 4.  [Book is a 2nd edition, so the supplement may have been added with this edition.]  The binding is too tight to find the sewing, so I can't tell which leaf in either groups of 5 is the extra.
  Here's my stab at a signature statement:  	pi4 2pi1 1-16⁸ 17⁴ chi1 18⁴

Did I handle the odd leaves correctly?

--Ken Rockwell