FBI 164-81, Vault Part 96 p. 14 (DB Cooper-42912), Letter, serial PD 164-41-1346 (as read from the transcript) — cooper.theunsolved.net/parts/Cooper-Part-96/pages/14
The scan is the source; the transcript is machine-generated from it.
Mr. Mattson
a few weeks ago while
reading these two publications,
the image in Time
startled me. I have
been reluctant to act
because of the absurdity
but the thought still
nags me. [guess: It's] even
thought that the money
may be in a vacuum
cleaner bag. So for a
10° long shot, the two
pictures are enclosed
for your review.