Bobcat, some of your references are not quite correct.
Here are the results I found:
WHO DOES 1TIM 6:15-16
APPLY TO?
Jehovah - w1931 3/1 p. 76 para.2
In 1 Timothy 6: 16 it is stated that
originally God only had immortality.
Jehovah - w1932 4/1 p. 104 "The Dawn Of
Creation"
God is invisible to man, and always
will be. It is He "who only
hath immortality, dwelling in the light which no man can approach unto; whom no
man hath seen, nor can see; to whom be honour and power everlasting". (1
Tim. 6: 16)
Both Jehovah and Jesus - hp42 p.44 - (1942 "Hope in a Righteous
World")
The apostle Paul, writing, of course, prior to
the return of Christ Jesus and the setting up of the Kingdom, says of God:
"Who ONLY HATH IMMORTALITY, dwelling in the light which no man can
approach unto; whom no man hath seen, nor can see: to whom be honour and power
everlasting. Amen." (1 Timothy 6:16) Had Jesus been immortal when he came
to earth he could not have died
as a ransom for humankind; but now since his resurrection from the dead, at
which time God clothed him upon with immortality, the foregoing text (1 Timothy
6: 16) also applies to Christ Jesus as the only immortal creature of God.
Jesus - w1948 10/15 p. 317
the apostle Paul said of Jesus at that
time: "The King of kings, and Lord of lords; who only hath
immortality." (1 Tim. 6: 15, 16)
Jehovah - w64 7/1 p. 406 par. 10 "Fully Accomplish
Your Ministry"
You may wonder how frail, mortal creatures could
possibly reflect Jehovah’s glory, when no man can see his face and live. (Ex.
33:20; compare also 1 Timothy 6:16)
Jesus - w66 1/15 p. 39 "The Sign of the Son of
Man"
Like his Father, Jesus now "dwells in
unapproachable light, whom not one of men has seen or can see."—Acts 1:11;
1 Tim. 6:15, 16.
Both Jehovah and
Jesus? - w68 9/1 p. 520 Is Your
Soul Immortal?
At 1 Timothy 1:17 and 6:16 God and Christ are
spoken of as being immortal, or incorruptible.
Jesus - w69 8/15 p. 484 Christ's Return—What Does It
Mean for You?
As a mighty invisible spirit creature, the
resurrected Jesus "dwells in an unapproachable light," and "not
one of men has seen or can see" him.— 1 Tim. 6:16.
Jesus - w08 9/15 p. 31 par. 2 Highlights From
the Letters to the Thessalonians and to Timothy
1 Tim 6:15, 16 - Do these words
apply to Jehovah God or to Jesus Christ? These words
apply to the one whose manifestation they describe, namely, Jesus Christ.