I don't think the HG-30 would work - I think it is a cassette, not a freewheel.

I bought one of those 11-28T freewheels for my Citizen Tokyo. On the good side, it arrived quickly in good shape, and works great. The 11t high gear was just what I needed and on the 16" Tokyo, the 28t low gear is quite low enough. On the bad side, yes, the shipping price was a little ridiculous. If this were a US company, I wouldn't pay more than the price of a "if it fits, it ships" US Postal Service Priority Mail box. But I don't know what it really costs to ship from Canada.