I need the image at Actual Size at 300 dpi to print. Otherwise it cannot be printed.
Below is a screenshot, the pink area is A4, the image you sent is actual size at 300dpi. As you can see it's too small. Also you can see in the square preview box that the image is not sharp, this is because it has been resized.
Resizing the image in photoshop means it will still look no good when printed. You need to scan the image from the old brochure at high resolution, like 1200 dpi or more. If you do not know how to scan, I can scan from the brochure you supplied.