Surface Pro 3 cracked screen help please!

You have already 'supported' the customer by telling them that  1> Microsoft cannot replace the screen 2> They cannot refurbish the machine 3> Installed FUD by claiming some 3rd party refurbishment will 'brick' the system.

Well it sounds to me like he has nothing to lose trying to do what many thousands of refurbishment shops around the world do on a daily basis. Granted they usually work on Apple machines because it is more profitable because there is a flourishing market in their parts from Chinese suppliers and they hold thier resale value better. 

If you do not believe me take 30 mins out of your day to learn something new

https://www.youtube.com/watch?v=tuOp29pPC_Y

Microsoft never replaced screens, even when they were servicing SP3 hardware.

They exchanged for refurbs (which you can't do any more as SP3 is discontinued).

Even if you were to find a third party screen, most vendors that attempt this

repair end up bricking the device. Unfortunately, you need to purchase something

else at this point to replace your SP3.

The problem with this is that if a customer attempts this, we can't support

other hardware issues or software issues. But most of the time, the result is a

bricked Surface or one with other problems.

If you are feeling bold and adventurous you could remove the cracked screen and look for the manufacturer and the unit code . Alibaba is a good place to look for replacement parts. I cannot guarantee you will be successful in finding or ordering the part but it is perfectly possible to replace screen without 'bricking' the whole system. Many of these displays are attached with just a ribbon cable that can be popped in and out very safely and easily.

It sounds like you have little to loose, just remember to order the glue strips to attach the new display to the chassis.