A little while back on sci.space.history someone asked about the "invoice" that Grumman sent to North American Rockwell for "towing charges" involved with Apollo 13. I finally found a newspaper article that has been copied countless times. I have no idea where it came from originally.

'Towing' Fee Is Asked by Grumman

An invoice arrived yesterday at the Houston office of North American Rockwell, the company that makes the Apollo command and service modules. It was from the Grumman Aerospace Corporation, builder of the lunar module, the moon-landing craft that turned unexpectedly into a "lifeboat" on the Apollo 13 flight.
Grumman listed total charges of $312,421.24, mostly for use of its LM for "towing" the crippled North American Rockwell craft most of the way to the moon and back. It was a service that the LM, primarily designed to use power only for brief solo trips from lunar orbit to lunar surface and back, was called on to perform when things went wrong aboard the service module on Monday night.
The invoice was drawn up, tongue in cheek, by a Grumman consultant pilot, Sam Greenberg, on Wednesday evening. He did it during intervals in a test he was running at Grumman's Bethpage, L.I. plant in an exact duplicate of the Apollo 13 LM.
The test helped work out procedures for transfer of electrical power from an LM to a command ship -- a procedure, the revers of normal, that the Apollo 13 crew had to resort to because of the loss of main power after the Monday night oxygen-system blast.
North American Rockwell, on receiving the invoice, had its Houston auditor examine it. Then the public relations director of its Downey, Calif. space division, Earl Blount, with a poker face issued a statement. He said that Grumman, before issuing such and invoice, should remember that North American Rockwell had not received payment for ferrying LM's on previous trips to the moon.

OK, now the invoice is much harder to read on my photocopy. The invoice, for anyone who cares to check records, is A441066.

The top block looks like who the invoice is made out to. Three companies are listed:

North American Rock
Pratt & Whitney
Beech Aircraft
The date (of the accident, I presume) is listed as 4/13/70. On the next line are "Houston" and "Cash" but I can't read what the block is asking for. The second block is a detailed list of charges. I show ??? where I can't make out what's in there.

First, there's some sort of serial number, then an item that says VIA is answered "IX-7, USS Iwo Jima, OCVAIR". Then a question is responded to by "None" and another on the same line "Never Again".

ITEM	QTY 	Unit		Description			Unit Price
1. 	400,001	MI	Towing, $4.00 first mile, $1.00 each	$400,004.00
			additional mile, Trouble call, fast

2.	1	???	Battery Charge (road call + $.05 ???)	       4.05
			customer's jumper cables

3. 	50#	#	oxygen at $10.00/lb			     500.00

4. 	1		sleeping accommodations for 2, no TV,	   prepaid
			air-conditioned, with radio, modified
			American plan, with view
			(contract NAS-9-1100)

5.			Additional guest in room at $8.00/night	      32.00
			(1) Check out no later than noon Fri.
			4/17/70, accommodations not guaranteed
			beyond that time

6.			water					  no charge

7.			Personalized "trip-tik", including all    no charge
			transfers, baggage handling, and 
					sub-total		$400,540.05

			20% commercial discount + 2% cash
			discount (net 30 days) 		    (-)	  88,118.81
					total			$312,421.24

			No terms applicable (government contract)
At the bottom, there's another reference to "USS Iwo Jima" VIA "Air Express", an answer to some question with "NASA (MSC)", and a signature at the bottom that looks like "Lew E [something]".

The caption beneath the reproduced invoice reads: Bill sent by Grumman Aerospace Corp. to North American Rockwell, prime contractor.