I'm not commenting one way or the other about the "Truman chips" or the other stuff, but a quick google search brought up an interesting page concerning giveaway items that LBJ handed out:

http://www.lbjlib.utexas.edu/johnson/museum.hom/giveaways.shtm

"Political Leaders have routinely expressed their respect and friendship for their contemporaries with gifts. President Johnson was no exception. As Senate majority leader and as Vice President, he was accustomed to distributing inexpensive token such as pencils, ballpoint pens, and pins—one in the shape of a Western hat.

When he became President, Johnson ordered a variety of objects to present to visitors and special quests. He kept a selection of appropriate gifts in a special "giveaway" drawer in his desk in the Oval Office.

These "giveaways" ranged in quantity and quality from cigarette lighters, pens, and small pocket knives to Accutron clocks, marble and silver bookends in slipcase, and gold Rolex watches. Other gifts included medallions, small-scale reproductions of a sculptured portrait by Jimilu Mason, autographed photographs, photo albums, Western hats, and cuff links—both solid gold and gold-plated. Most gifts bore the facsimile signature or cipher of LBJ, the Presidential Seal, or the inscription of the Golden Rule: "Do unto others as you would have them do unto you." An especially prized gift was a small charm of a water well, recalling the old Western compliment that the recipient of this gift was indeed someone who "will go with you to the well and back."

List of Presidential Giveaways
The following items are assembled as giveaways by President and Mrs. Lyndon B. Johnson:

LBJ Busts

Note Stationery depicting the Boyhood Home of Lyndon Johnson

Inaugural paperweight with Lyndon Johnson medallion on wood base

Travertine square block with LBJ coin embedded

Bookmarks made from deer skin from LBJ ranch with Presidential seal and signatures of President and Mrs. Lyndon Johnson

Silver coins with Presidential seal

Card Tray-glass with seal of President and signature, also inscription reading
Air-Force One

Tiffany's letter opener with seal and signature

Framed prints: President's House, Johnson City High School, others

Flags flown over the White House

Blazer buttons with seal

Paper covers for wastebaskets with various photographs of the President and family (Lynda's wedding, Mrs. Johnson planting a tree, President Johnson speaking, etc.)

Playing cards with Presidential seal and name

Playing cards with Air Force One seal and name

Pens and pencils of all types and sizes with seal and signature

Cigarette packages with Presidential seal

Plastic Snaplock holder with Leatherette cardboard holder of small medal

Lucite bookends with medals of LBJ embedded

Lucite embedment 2 1/4 x 2 3/4 with three (3) minute sand timer for small medal

Paperweight for Hollybush similar to inaugural one

Watches: LBJ inscribed on face, "Do Unto Others..." inscribed around face

Charms

Key Chains

Tie clasps, tie bars, and tie tacs with: Presidential seal, LBJ, Air Force One,
Hat with LBJ

Cufflinks with LBJ

Lighters with Presidential seal and/or name or initials

Electric Shaver with Presidential Seal

Electric Toothbrush with Presidential Seal

Ash Trays, some with map of the LBJ Ranch, some with the seal and LBJ

Wooden boxes with Presidential seal and LBJ

Silver Cigarette boxes with seal and name

Gift wrapping paper with the White House seal

Various statements by President Johnson printed and adorned from framing
with the seal and initials or name

Leather encased pocket knives with Presidential Seal, penny inside

Crystal bird with Lady Bird signature

Silver calendar

Wooden bookends with Presidential Seal

Perfume dispense with seal

Inaugural address in address book (pocket) size

Crystal match holders with seal

Crystal bud vase with seal and signature

Crystal bowl (serving size) with seal and signature