Self-Inflicted Editing Wound

[AllQuiet]

Greetings to All- I have got myself stumped here and would appreciate some direction from the experts here. For pokes and giggles, I modified a couple of the vessel files inside the default folder...namely, the SeaWolf and the Alpha. But I've been looking at so many files and lines of code, I've become cross-eyed and stumped.
For a quick rundown, the files I've edited are as follows with their respective folders ( keep in mind these are the oem files)

Default Folder:
config
single001-017

Default\hud\damage_control
brought in the respective files and masks for Oscar, Alpha & Akula

default\language_en\mission:
missions_single
single001-017

default\vessels:
wp_ssn_alfa
usn_ssn_seawolf

default\language_en\vessel:
usn_ssn_seawolf_description
wp_ssn_alfa_description

For pokes & fun, I tweaked the following:
Cavitation speeds/depths
Submerged speeds
Acceleration/Deceleration rates
Dive/Surface rates
Escape/Test/Periscope Depths
Self Noise values
Anechoic Coating True/False
Towed Array Models substituted and tested
Torp Reload times
Noisemaker Counts and Reload times


Thus far, all of the edits that I've made have worked without issues.

Here's the ditch I'm currently in.
I want to add the Akula & the Oscar to the list of sub option I can select from when I run the basic 17 single missions.

From the Default's root folder, I can edit any of the single mission to include a list of vessels I can run for the given mission by the statement to include:
PlayerVessels=usn_ssn_narwhal,usn_ssn_skipjack,usn _ssn_permit,usn_ssn_sturgeon,usn_ssn_los_angeles,w p_ssn_alfa,usn_ssn_seawolf,usn_ssn_los_angeles_flt 3,usn_ssn_los_angeles_flt2

Works great. Now I wish to add the oscar and the Akula by including it in the PlayerVessels list, as in-
PlayerVessels=wp_ssgn_oscar,wp_ssn_akula1,usn_ssn_ narwhal,usn_ssn_skipjack,usn_ssn_permit,usn_ssn_st urgeon,usn_ssn_los_angeles,wp_ssn_alfa,usn_ssn_sea wolf,usn_ssn_los_angeles_flt3,usn_ssn_los_angeles_ flt2

So I make the necessary edits for Oscar, Akula & Sierra to be added to the list of options for single mission choices.

Kill program, relaunch, select mission, opt for the Oscar, confirm the Oscar...then expecting the loading screen, instead the program just draws a blank screen, forcing me to kill the app and look for anything I've missed...same results when I opt for the Akula.

Now the reason I've gone this route, instead of using the override addon that allows us to drive almost any sub in the game, I have personal handicaps with severe arthritis in both hands makes determining vessel ID painful after running thru 40+ signatures. The addon takes that number to around 140+ or more if memory serves- and at 60+ years of age, memory can be fun or agonizing.

Now, if I knew how to cull out certain subs, and their respective linked files, I would be fine with that...as the AddOn mod that was made available to the public is a whopper of a kind gesture and considerable efforts that were put into the release.

So, while this article definitely ranks up there with the TLDR label,
could someone help me make the Oscar available in the single missions...hoping I made myself clear on the steps I took and probably overlooked or missed something small or something critical...since I've had success with modding the SeaWolf and Alpha, I' at a loss why the Oscar and Akula edits bring things to a halt...

Could I get a hand extended for some help adding Sierra, Oscar, Typhoon, Akula and Virginia?

Many Thanks to the contributors and board operators.
AllTheBest- AllQuiet