Help removing front valnace

[AlbatrossCafe]

I am trying to remove front bumper and valance on my 1978 280z to make way for a new air dam.

I am stuck removing the valance. I got all of the obvious bolts out, but there are 2 issues:

1. The side fender and valance appear to be "fused" together?
2. The last few bolts have some kind of gunk/material that is nearly hard as rock stuck on them and I can't get to the bolts.

I thought the valance was 3 pieces. It looks like where the middle and side piece attach, there is a ton of gunk around the bolt that holds them together. WTF is this stuff? 2nd pic is zoomed in on area of first pic:

 

Secondly, why do the fender and valance appear to be fused together at the seam? I didn't really want to take a screwdriver and hack at it... also, behind the valance in the 2nd pic below is another bolt that has a ton of gunk. No way I can get a socket or wrench around it.

 

Any tips for getting these last few pieces out?

Edited January 15, 2018 by AlbatrossCafe

[wheee!]

Looks like a ton of underbody coating on the mid to side sections. The side valances look like they have been siliconed onto the fenders. No easy way to pull that apart... have fun!

[gwri8]

I'm guessing you want to try to save your paint right?  So, If it were me, given the description of the foreign material, my first weapon of choice would be a heat gun to soften the gunk along with a small putty knife do a little digging.  I would start on the center piece first.  Once that is figured out,  then be very gentle with the side pieces.  Good Luck!

[AlbatrossCafe]

It is likely underbody coating. It's what kept this car mostly rust free but makes stuff like this a HUGE pain.

I am reading about silicone and that sounds like what it is. That at least gives me a direction to start in. Thanks.