"Ach, a man on a galloping horse wouldn't notice it" - used to refer to slight or slightly more significant imperfections/ corner-cutting in building work... 

"I'm not as dumb as I am cabbage-looking" - I can only assume that Tony thought cabbages were the stupidest of all the vegetables...

"Spuddling" - According to the urban dictionary has many definitions - to Tony, spuddling was more akin to interfering, causing mischief using your words.... or to use the bonefide urban dictionary definition which has now (2009) caught up with Tony:

To deliberately attempt to deceive a friend with a tall tale, for the purposes of humour. The majority of spuddles are low-level, with the key ingredient of a spuddle being believability, but some can be outrageous, as detailed in the example below.
Chris: "Oh Russ, I forgot to tell you. You see my mate Ben, over there? He's Chuck Norris's nephew!" 
Russ: "Really?!" 
In this example, Russ has been Spuddled. He now believes that a friend of a friend is related to the actor and Karate expert, Chuck Norris.

"Better than a kick in the arse with a frozen Mukluk" - A variation of 'better than a poke in the eye with a sharp stick'  A mukluk being an animal skin boot often worn by indigenous people in the arctic regions, ie Canada where Tony spent many years and was a Citizen. We assume a frozen one would be pretty solid and painful.