Attempted Removal of Kryptos Additive

If Kryptos goes into the 98 characters of K4 14 times by addition or subtraction, what is the underlying ciphertext after removal of the additive?  What’s the worst possible way of showing how I did that?

Oh, wow, I don’t even want to look at that spew of numbers and letters.  Here’s what I did in a nutshell

1. Turned the 97 characters of K4 into their respective numbers, leaving ? and A=1, B=2, etc.
2. Turned KRYPTOS into numbers (11-18-25-16-20-15-19)
3. Put them onto an overly complicated spreadsheet that let me add or subtract them.  We don’t know which way they were originally – added or subtracted so you have to consider both.
4. Take the remaining sum and convert it back into letters
5. Post another horrific picture of the result

So now, hopefully, I have removed the masking technique which was a simple and classic super-encipherment involving an additive being added or subtracted from the primary cipher-text.

And now we can hopefully move on to consider how to remove the remaining substitution to get to the plain-text.

This is all hopeful, I have no guarantees that I’m doing it right.

Here’s the text in copy and paste-able format:

SUBTRACTING:

?WCUX-FVMWH-RAWIH-WMSLMILNMB-BBXEZ-OQQDZ-DBXDW
DQFAT-OQKGL-IUTQW-BSQBG
OYMQV-ZZBEA-BHGPQ-HNSSA
HZUJS-QHUAS-BPCFU-ILY

ADDING:

?GAAL-JHIGF-XOASD-GKYZQ
UHXKH-PFJAJ-MWEHL-ZLVJK
HCBKR-UEOSH-SSZEA-NOAZM
CCYMF-XFPIM-XREFE-LZOCYNNYVO-AFAOW-NLMDA-WPK

Good luck!

-Kryptosfan