We purchased a Simpo Sign Stand earlier this year. Can I just buy replacement signs to go in the stand we already purchased?

Yes of course. Simply visit our Coroplast Signs page and purchase 22" x 28" signs. This is the size that the Simpo Sign accepts. You will want to order two (2) signs, each printing 4/0 - full-color printing only on the front. Here is the link for our Coroplast product page https://www.4over4.com/printing/coroplast