Every tailwheel I've ever taken apart has had five springs, last week I took one of AK Bushwheel's Tailwheel apart and there were only 3 springs but still 5 holes, some of the early models had only 3 holes and 3 springs. The Brass plate you talk about needs the pins, when they break off is when shimmy happens. It amazes me how many shops and mechanics out there haven't got a clue how to service a tailwheel, just pumping grease into them isn't proper servicing. Take them apart and wash the dirt out of the inner workings and replace worn parts and you'll be amazed at how much better your ground handling is. Of course Alaska Bushwheel is the de-facto source for parts these days for every model Scott that was ever made, and I might add their quality is a hell of a lot higher than the original Scotts too. The Dowel Pin bottoms out at about a quarter inch, drill a small hole in it and use an easy out, with a little pull and reverse twist they will usually come out. I've not tried to remove the new style dowl, they look like a roll pin instead of a dowel pin. The heigth of the dowel pin shouldn't be more than the thickness of a new thrust washer, large brass or bronze rings 2ea. if you replace it and it's higher than that it will rub the steering arm. (actually I'm thinking of the time I made one by cutting a 3/16th bolt down to size and used it for a pin because I thought the price quoted for a little pin was excessive). One more plug for the BW guys, the tailwheel attach bolt with the integral tie down ring gets my vote for "best improvement product" of the year, maybe its just me but I hate getting grease on my hands and grease on my ropes. And Binty if you run into my Wife's friend Cathy Penny, give her a howdy from Salt Lake. She works Helicopters for the NZ FAA or whatever the controling agency for aviation is there. good luck with your tailwheel
Dennis