Hello Ms Billman and all of your transcribers!
The old Greek Lambda (looks kinda-sorta like a mathematical "less than" sign) is actually a Phonecian version of lambda.
Beyond this application, I have most often seen the "chicken foot" used in set theory in mathematics. There it commonly known as the pitchfork (unicode U+22D4).
Because there are no established braille symbols for these in UEB or other natural language braille codes, it will be appropriate to use transcriber-defined symbols for these print characters (RUEB 3.26). These will fulfill what RUEB 13.6.2 considers "category 1" - signs representing the basic elements of the script (whether alphabet, syllabary, or other).
These should be included on the Special Symbols page in the category for non-English language symbols. All the usual criteria for representing non-English languages in your document will apply.
Please let us know if this answers your question, and/or if you have follow up questions!