Make your own
I do not know how large a press you need. I have a press so I have not tried the following suggestion. Buy 2 pieces of 1/8th inch aluminum that will fit into your oven...replace the oven rack with the aluminum that is cut to size to fit. Attach a wooden handle to the upper piece. Use 2 pieces of mount board that are preheated with the alumninum. Pull the sandwich of mount board/ aluminum pieces out using gloves such as a cook would wear. Set it on the counter top, insert your print. I would hazard a guess that you will be able to mount your print without even returning it to the oven. My own experience has indicated that most tissue will melt much quicker than most directions indicate. Remove your print and return the sandwich to the oven to reheat for the next print. You might even consider buying 3 pieces of aluminum and use the 3rd piece as a press to cool your print under.