I have a whole group of Matt Helm novels with no ISBNs.  They were published in the ‘60s and ‘70s.

(The links are to a version of the book in the system):

The Poisoners   Author: Donald Hamilton

Matt Helm - The Shadowers      Author: Donald Hamilton

Matt Helm - Murderers' Row   Author: Donald Hamilton

Matt Helm - The Ravagers   Author: Donald Hamilton

Matt Helm - The Wrecking Crew   Author: Donald Hamilton

Matt Helm - The Betrayers    Author: Donald Hamilton

The Interlopers (Matt Helm #12)   Author: Donald Hamilton

The Devastators (Book #9 in the Matt Helm Series)   Author: Donald Hamilton

The Silencers (Book #4 in the Matt Helm series)   Author: Donald Hamilton

In addition I have the following on my shelf.  Link is to the actual ISBN on my book.

THE DETONATORS (Matt Helm, No 22)   Author: Donald Hamilton

THE AMBUSHERS (Matt Helm)   Author: Donald Hamilton

The Vanishers    Author: Donald Hamilton

The Menacers   Author: Donald Hamilton

Retaliators    Author: Donald Hamilton

THE INFILTRATORS   Author: Donald Hamilton

Intriguers    Author: Donald Hamilton

THE FRIGHTENERS   Author: Donald Hamilton

The deal:  2/1 on up to 8 books.  If you take 9 books or more, 3/1.  Will send you the entire set of 17 for five credits.  PM me.

   I will take the 17 Donald Hamilton books for 5 credits.  I have ordered 1 book from your bookshelf for mailing info. and will transfer you the other 4 credits when you confirm my  order.    Thanks,        Clyde/HookieJ

Hi Clyde, I just separately PMed you about this.  WIll PM you again.