Don't forget that Troop 168 has a library! Many pamphlet titles are available to Scouts as they begin working on specific Merit Badges. Scouts simply need to sign the pamphlet out (and return it when done.)
Boy Scout Advancement Requirements Changes as posted on USScouts.org:
The Guide to Advancement - 2017 and 2018 Boy Scout Requirements are the official Boy Scouts of America sources on Boy Scout advancement procedures.
When there is a conflict between two published lists of requirements, such as Boy Scout Requirements (BSA Publication No. 33216) and a Merit Badge pamphlet or the Boy Scout Handbook, the requirements book should normally be considered to be the controlling document, until a newer edition of Boy Scout Requirements is issued. However, the following excerpt from the Guide to Advancement- 2017 explains what to do when merit badge requirements change:
126.96.36.199 What to Do When Requirements Change
The current annual edition of Boy Scout Requirements lists the official merit badge requirements. Once new or revised merit badge requirements appear in this publication, which is released each January, any Scout just beginning work on a merit badge must use the requirements as stated there.
If changes to merit badge requirements are introduced in a revised merit badge pamphlet after the January release of the Boy Scout Requirements book, then the Scout has until the following January 1 to decide what to do. He may continue—or begin work—using the old merit badge requirements and the old pamphlet; or he may switch to—or begin work—using the new requirements and the new pamphlet. Unless it is otherwise stated in the merit badge pamphlet, Boy Scout Requirements, or official communications from the National Council, if a Scout chooses to use the old merit badge requirements and pamphlet, he may continue using them until he has completed the badge.
There is no time limit between starting and completing a badge, although a counselor may determine so much time has passed since any effort took place that the new requirements must be used.
188.8.131.52 The Benefits of Merit Badges