Press kit contents varied based on function. Normally they came out at the start of the model year, going to wire services, newspapers and (sometimes) radio and TV stations). They contained varying numbers of photos (depending on what was new that year and what models were offered) along with a few press releases highlighting the features and models. Having brochures in them was not normally done and a prior model year would not be included at all. To illustrate, I have 2 different versions of the 1946 release announcing the 1947 model year cars and the Rototiller. Version one is the package that went out in January of 1946, with Version two being the one that went out to West Coast news organizations and dealers to tie in with the first showings of production Kaiser and Frazer cars in the Los Angeles and San Francisco areas (Mine is an SF version as it talks about introduction of the cars in the Bay Area). The SF version shows only the K-100 Special and there are no items pertaining to the K-85.
When kits were released at major auto shows (Detroit, Chicago, NYC, etc) there would usually be at least one press release talking about anything special being introduced or shown at the K-F display. I don't know of any 'master list' as to what was in a kit at any given point other than to go through survivors and compare contents.
I have the 2 initial kits, a handout package for dealers at the 1948 Spring Driveaway and the press kit for the Kaiser-Darrin, 1953 edition. I have press releases and photos loose from others.