No prob Sirius - I could tell you were itching to get into the depths of the IF-150 !
I think you nailed it in your earlier comment when you suggested that the HF-150 supported an alternative command set that the keypad was not designed to send. Spot on. That prompted me to look into what the IF-150 was actually spitting out.
Incidentally, since I sent the scope shots, I found this site that you may find interesting:-
https://www.nick-bailey.co.uk/if150/
Jerry