To me, the letter was hurried, but also sounds dictated by someone else; I see the writer anticipating the next word of the composer and stopping in time to cause the hesitation/"do-over" marks. He/she either added "to" in front of" get" after "get" was written, or regularly thought of it as one word.."toget"... away, but it looks tight. Then re-entering the correct apostrophe for "we're." It's entirely possible this was a draft, but either there was only one piece of paper and it "had to do," or the composer (male) wasn't physically with the writer (needed 'female' writing) to see the obvious mistakes and have it done over. So, a phone call...."quick, get a pen and write this down..." I'm sensing someone trying to be grammatically correct and proper (sidenote: "Thomas") who actually wasn't him or herself.
Then the change of mind or afterthought on "Houston." That wasn't the original letter, which looks like to be a "B", "C," "G" or "F" if a capital, but almost anything if not, and not certain it was a location. "We're going to be back by, wait no, we're going to..." Also a spacial pause after the "to," I see thinking on the fly. Plus, the period after Houston is so close and dark. Possibly written "We're going to . " and was filled in after the framework was written. He/she/they left a blank while they figured out what to write, then stretched the "n" in Houston to the right to fit. I think "see" was the start of "seeing" or some other word and was abruptly stopped but who knows. There are also a lot of higher pressure spots, bolded. Either to overwrite or some subconscious finality.
After seeing this note many times, my biggest takeaway this time is back to the original red-flag of "Rachel." I'd always thought someone had started to spell Rachel incorrectly. But looking at it now, the 2nd (wrong) "e" had a definite stop. Could someone had been writing "Rachel" but THINKING "Renee," and wrote Rachee...then fixed it? They'd already gotten the first "e" correct, so why is their brain seeing another one? If you knew the spelling as RachAel, you'd have written the "a" first and the overwritten letter doesn't look like an "a." If you were writing "Rachle" by accident, you'd have already blown it and be trying to hide a tall "l". This might be a reach... but if you're writing an "h," it's the same endstroke as an "n," and "nee" could have been the result of someone thinking "Renee." If it was an "n" it looks like a match to the one in "going." Further, if there was the same huge space after the R in Rachel as their was with the T in The, I can even see it signed "R enee" originally, with the "n" converted to an "h" and the "a" in Rachel added afterward, albeit pretty smoothly. Overall, the double "e" in "week" looks natural, as does the word "upper," so unless this person was truly ambidextrous, I don't think it was an attempt to write with the non-dominant writing hand. But it's jerky and possibly not written in full the first time. Curious if schools were already teaching manuscript rather than script in the early 70s? That could narrow the age range (of the writer, anyway). As I've said before, "catch it" sounds like a regional thing to say, as in, I don't think whoever wrote this was from the Bronx.
"I know I'm going to catch it, but we just had toget away. We'r'e going to Houston.Seei you _in about a week. T_he car is in Sear's upper lot." Love R_enee or Racheel
I don't think the way it was ultimately made to be read is what it originally said, even before the signature.