Replacement Glass Door Slider Tandem Rollers

I've pulled a pair of roller assemblies from my Winchester Tri-Pane Glass Door Slider and they match up quite nicely with your P/N 81-018, with one exception. The two mounting tabs face the opposite direction. Instead of being at the bottom (near the wheels) they're at the top. Can you provide replacements for these? If you would like me to send a photo, please e-mail me. (Your "image upload" application isn't working properly.)