TSB = Technical Service Bulletin
TSBs were issued after the factory service manuals were released to note changes / corrections / or fixes to commonly occuring problems during new model years. They can also note parts substitutions and so on.
I have a lot from '69 and '71, but only for the Plymouth / Chrysler / Imperials. I have very few for 1970 and very few of any year for Dodge models. I am hoping too fill out my collection by trading my duplicates for the ones I do not have. I will scan them and add them to the HH website for all to use as I get them, the '69 TSBs will be the first ones ready to view.