Glyn,
If you are talking about the black 3" male or female NPT threaded ABS collar
with the toilet attachment and screw-down four bolt holes, those are readily
available and cheap. I have spent hours of research for this exact same
thing, but need a 1 inch offset for the modern toilet which requires a 11"
center instead of our 10" centers. I have recently purchased two of the 3"
male threaded flanges. My thoughts are to marry one to the altered other and
weld together. These were on the shelf at almost every hardware store.
I also could not get mine to unscrew. I used a sharp chisel and gently broke
away the old one in pieces by chiseling from the sides, not from the top. I
chiseled in the direction of removal which is counter clockwise looking down
upon it. By the time I had chiseled about half of it away, it finally
released. I did use Kroil once I had exposed the threads in one area. I
soaked the joint threads and continued to chiseled away pieces. It finally
released but had it not I would have chiseled the whole thing out. In some
areas I gently used a cut off wheel grinder to make the abs flange thin,
almost grinding thru, but stopping, then chiseling. I also took my sawsall
and partially sawed thru the threaded vertical hole, careful not to go thru
the side-wall and into the threaded area. I was determined to get it out,
and did. The result was the old flange out, perfect tank and threads, ready
for new flange.
Now I cannot find a 1 inch offset flange. Still stuck, I will probably have
to make one.
-Eddie- Houston, TX