Questions like this come up a lot here. My thoughts as always, are
ask a certified mechanic with repair experience/authority on your
particular make and model. If you can't find such a person, contact
the Mfg. They are the Overarching Authority in a case like this,
unless of course they are out of business, where you have other
options. Before you do, read the repair manual so you can accurately
describe the water location.

FWIW, The HK-36 has an excellent treatise in the way of a S/B on this
problem, albiet in the spoiler box, not the wing LE. Google up the
Diamond_at (Austria) website at look at the service bulletins.
Sorry, I am not going to take the time to reward your post on RAS
with an easy link!.

For visual inspection, you don't need a boroscope anymore than you
would use a film camera. I am sure you know someone with a newer
digital camera you can borrow or rent- Most have HD video
capability. Again, a competent repairman can best interpret/document/
sign off the results, and with the right materials can cut a hole and
repair it if you don't have an access hole where you need it.

Most people that work at the big companies are not exposed to the
specific aspects of glider construction at the workplace. If they
did, they would probably say to contact the Mfg or repair station with
a appropriate licence - that is what their customers do. BTW, NDI
methods such as ultrasound (A, B, and C scan), lazer UT, shearography
and X-ray require a standard, your source seems not to have mentioned
that to you.

Don't suprised if a repair station wants to see the ship and charge
for an inspection. That means they are likely trying to be competent
and responsible, or at least limit liability. Spend the money and
time to get an legal/expert opinion. This board IMO is not exactly
the glider equivalent of WebMD...

BTW, are you sure your ear is good enough to tell if there is a delam
in the inner most plies of the solid laminate of the LE overlap
splice? If I was water, that's where I would go, right through the
exposed edges of the trimmed sandwich shell laminate at the splice.

Not trying to scare you, I think you can get this resolved quickly,
leagally, and possibly have insurance cover the cost!

aerodyne