There are listed four aircraft: Vought F4U-5 Corsair (1/97), Grumman F6F-5 Hellcat (1/96), Lockheed F-80C Shooting Star (1/98), and Vought F7U-1 Cutlass (1/86). Indeed  I did not find more than those four types until now and I came upon bagged and boxed issues.

Remark * : This may be a typo, which I think should read as Trim Molded Products.

The inscriptions  printed on the instruction sheets reveal that Trim Pak was just a brand name, the manufacturer proper was Trim  Molded Products Co.  Inc. Wisconsin USA.  A search in the internet yielded that this company produced also plastic toys. Two examples are the Soda-Pop Fountain. and the Kool Aid Dispenser [2] and [3]. From the inscription on the  box of the latter I found out that Molded Products Co, was a subsidiary of Aluminum Specialty Co Manitowoc WI. This company produced aluminum houeswares [4] and the legendary Evergleam aluminium chtristmas tree [5].

The boxed and bagged issues of the Cutlass show a copyright date of 1957, the boxed F-80C a date of 1957 as well. The bagged Hellcat has a copyright date of 1956.

I have no access to copyright dates of the boxed Hellcat and the two issues of the Corsair so I cannot confirm the statement in PAK-20 that "These kits were issued in the early 1950's".

List of Kits
These are the aircraft kits I can confirm having them in my collection or by third party pictures. These four types correspond with the list in PAK-20 quoted above.

Type of Aircaft	Bag	Box
	Kit no.	Kit no.
Corsair F4U-5	A-2 *	-
Hellcat F6-F	A-3	AA3 ?
F80-C Shooting Star	-	AA12:29
Cutlass F7U-1	A-13	AA13:29

 * This kit is pictured on  Worthpoint, which confirms its existence.