Well if its retaining the vacuum, u shouldn't feel the pedal rise at all,and u should be able to walk out to it now and push the pedal down and still hear the air noises. Did u pull the brake servo pipe out and see if the vacuum was still there?

So, let me get this straight, your going to clean it up, and re-seat it with something both STICKY and STRONG

Just get a new servo man, i bet its the orignal one the car came with anyway, if you've put a whole new braking system on why not just change it and make the set, i think off the top of my head they're about £25, chances are if u seal the front it will spring another leak somewhere else. Cutting corners never works in the long run.

But before you even do that why don't u just disconnect the servo pipe and block it at the manifold and see if it runs then???????