@jimi, phewwwwww....that was a journey eh?...success!... 
see, it can be done!..without a tick... 
this is why i strongly recommend 'breadboards'..... i bb everything!.
@neutron: i tried various 555's and all ticked apart from the ts555cn...when it had a 2.2k on the power...
this may obviously vary due to tolerances or ic you are using etc...try what perrow suggested, to find 'that spot with a pot ' ok.
rob and everyone, thanks so much!
yah, it works perfect. i DID find two possible mistakes on the layout... i didn't use a dc jack, so i use a 9 volt battery clip wired to the b+ connection on the board, with a switch to break the battery ground at the circuit board ground. so that was a very slight modification...
the three things i had to do to make it work were...
add a ground strap from the input jack ground to circuit ground on the board...suddenly it stopped ticking and motorboating, and worked great!
next, the bypass led...on the layout, it looks like the anode is on the top, cathode on the bottom. this is backwards! also, there's enough current to just pop an led..i blew out about 5 of them before i figured it out. i used flying leads to a little piece of perfboard, and added a 4.7 k resistor to limit the current...used a 1/4 watt one, and soldered it to the little piece of veroboard, then soldered the other end to (i think) the cathode side of the led...worked like a charm.
tried it with my twin, and again, my marshall...no ticking, no noise, just a really transparent, warm tremolo effect that kinda reminded me of a univibe a little bit in some circumstances.
if anyone else can't get it to work, but can see the led flashing inside the shrink wrap, try connecting audio and circuit ground, i bet it will work.
tried the other radio shack 555, no dice, no nothing...the led just lights and stays lit. if you're in the states, and go to radio shack, you need the one labeled tlc555 low power timer ic, linCMOS timer 8 pin DIP. part number 276-1718. and you should be good to go!!!!!!!!!!!!
i have to cut out to new york for the day, will try and post pics and some kind of demo when i get back...
if you're having probs with the circuit, try my suggestions, i hope they work for you...
the only other thing i noticed is when i turn my guitar down, it turns down QUICK with this circuit...so i imagine a tiny buffer at the input will do wonders...
but i don't know how to do that yet!
great circuit, fun toy, and a satisfying experience, rob....thanks again mate, especially for the patience while i sorted thru this!!
good luck, everyone...
peace,
jimi