I use rr spikes to hold mine down. i drive them in around the base. by the way, your anvil is marked w/ stone weight, so that would make it english .check for punch marks between the numbers. if it has those it is a mousehole.
definitely a PW. i would think 353 lbs 4.3 oz by the looks of it, but i would have to see it in person to be sure. no rely, it is probably in the 350-400 range. great find.
welcome aboard. for someone in your situation who is just a hobbyist, i strongly suggest Wayne Goddard's '50 dollar knife shop'. its a great book, and covers building several forges, and has great pics.
I've modified a well known mark twain quote to fit blacksmithing.
July is one of the best months to buy another anvil, the others being January, March, April, May, June, August, September, October, November and December.
I have big hands that have been strengthened by milking cows twice a day and being used for everything u can imagine. None of my friends will ever shake hands with me anymore.