The Home Machinist!

As mentioned in my previous post here, I was looking at an old Roper Whitney punch press. Desided a single operation punch, such as the C Frame in a good hydraulic press would work for me. Round holes, I can drill but often wish for square or oblong or key hole. While considering the Roper Whitney, I determined that it used the 28XX style dies and there are a lot of interesting possibilities. Plus this style is commonly available on ebay.
So I have been looking at a number of C Frame punches offered on ebay with some be affordable. However, the 28XX punch/dies and I am a bit confused when looking at the Unittool and Unipunch model description, even on their web sites. seem too large for these C-Frame holders and need to find out which dies the more common C-Frame punches use.
Unittool seems a model numbering system where the first number is the throat deep, the letter being the duty and the next number seems to be the holder body width. No mention of the die OD size.

I guess i need to determine the availablity and cost of dies before I jump in an purchase a C-Frame punch settup.

Any thoughts or recommendation of die sources for these punch/die sets.

Steve

Whitney and DiAcro had turret presses which were similar. Hand operated with the dies and punches rotated to the punch station together. Don't rmember the exact dimesions of the die holders which bolt to lower platen but DiAcro were and Whitney grey.