Too early in the morning for me, I forget what this project of yours is.
the short version is i'm getting my entire financial history put into a format that can be used to do accounting. i'm using a program called beancount to process the results.
the longer version (eyes glaze over in the audience - that's ok) is that i've already in the past typed some of my history into text files in columns and they've been a starting point for me to get other things done, but up until now i didn't work on the most complicated file of all which is my checking account from a credit union. they did not offer any kind of electronic version back then so up until more recent years it was all paper statements and then electronic ones, but the actual transaction history i could use was more recent. so all those old transactions that i typed in took me to midway through 2005 and then i stopped making entries. so the file is not complete, but at least i did not have to type it all in again to get this far. pretty much four days of editing though to get it all cleaned up and being more consistent and adding details as i recall them.
one mistake i thought i made threw me off until this last editing session where i realized i'd conflated two things into one and the positive numbers i was depositiing were actually correct when i though they were a mistake. it came back to me that yes, this one guy was renting a room and was paying me his share of the rent. so those lines had to be re-edited again and turned into Income instead of an Expense.
so getting those 1980 - 2005 entries edited and properly classified and fixed up to be more consistent was a five day project. and then the program i'd already written for another project was adapted to work for this one so that was another few days.

if you ever need a column/table wrangler type of program "petl" is useful and the computer language Python was fun to work with more for doing this... (i'm gradually making more sense of it as i'd not done too much with it before, in the past i've normally used shells scripts for the quick stuff and C for the more complicated things that i had to write lexical and parser grammers and then use those, but i'm able to do that easily enough)...
now that i have all those done for now i can move on to the paper statements and adding the years between 2005 and halfway through 2020 when i pick up with the current data. i'll have to go grab my checkbooks and see who and what i may have wrote on the recipts, but it is possible those are not legible any longer so i may only have the amounts and guesses...
I do understand your enjoyment of getting the data "right", though. Although, I have, on occasion, said "good enough". Lol
yes, i have to do some of that. guesstimating... many times i just withdrew money and called it cash but might not have kept any notes on the check or ... and at those times i also had old e-mail files to work with to give me context but those were lost and at one time i decided that even if i kept working on retrieving those files i didnt want to so i wiped it all including my recovery files and my backups to keep me from dredging through it. now i wish i'd kept it anyways. oh well...
when i get to that point i'll tag those entries with a code which means i'm guessing about it somehow.
i'm just glad now that i'm somewhat done with the longest running account (mostly done) and am working on the next longest running account (which is much more complicated) but now the first part is done so i can move on to the next part of it (money market acct), but i can reuse the tools i've already developed so that will speed it up quite a bit...
just to be on the homestretch of the project instead of the other end when i started out months ago... feels good and helps keep me going to know it will mostly soon be done (in a year or less).
in the meantime what i've done already is helping me keep current too. so i'm not as behind as i was before.