water pump installation

[Kneale Brownson]

I've always thought (and used the approach) that the big O-Ring is the 
only seal required on an I-5 waterpump.  I'm doing the timing belt on my 
200q20v avant, and when I took off the old pump, there was a bunch of 
black gunk all over the surface surrounding the hole.  After repeated 
scrubbings with brake cleaner and a brass brush, I've got all the black 
gunk off, and I find there are several grooves where the old pump sort 
of corroded to the block, I think.  This is only the second belt 
replacement, according to the records I got with the car, now at about 
130K miles.  I used some fine sandpaper and a sanding block to clean the 
surface after getting the black crap off.   I can see the grooves still, 
but they're fairly smooth.  I don't think I could get anything like JB 
Weld to stick in them enough that the surface would be smoother after 
additional sanding.

Anyway, the directions for "mounting" the new pump say to remove all 
traces of old sealant and apply "sealing compound--Curil--between the 
sealing surface and the new pump".  They also supply the O-Ring, of 
course. 

Because of the non-totally-smooth condition of this block, I'm tempted 
to use a sealant.  Never seen Curil before.  Any suggested alternatives 
I'm likely to find in a rural FLAPS?
_______________________________________________