Southbend apron interchange?

I have a SB 11" and I bought a used casting off ebay for it.
My fault I looked at the pictures and never really saw the difference in the 2 aprons.
Mine is built just like a 10K or 10L and the one I got is an older looking apron.I know will not fit.
I was wondering if anyone knows why the 10K or L would not fit? If I changed the 1/2 nuts to fit the 11" since my lead screw is 7/8"? any other reason it may not work?
Mine is secured to the compound with 2 large screws. I dont know about the 10" lathes?
Any input would be beneficial to which direction I need to go.
Thanks
R.

I think all the 10 inch lathe aprons are narrower than the 11, and the hole thru the worm would be too small. There could be any number of other differences too. What is wrong with your apron?

allan

I have owned the lathe for about 25 years and never had a thread dial. Did threading on another lathe.
I rebuilt the 11" totally when I first got it except for the apron which seemed to work alright, but where the mounting holes are for the TD the top one is broken out.
Actually pretty bad, missing some of the casting.
So I never fooled with it since I didn't need that option.
Now I have decided I would like to thread with it.
Even though the apron works alright I found a casting one eBay,
Bought it but was the wrong one.
Who would have thought they made 2 different 11" lathes back in the day.
anyway mine is a double wall with oil sump.
the apron casting I bought is an"O" model I think.
My experience with repairing cast iron is not worth the attempt.
Ron

Maybe I asked about the interchange of the wrong size apron.
Talked with a man today about my apron on the 11".
I have been looking for one, and have looked into using a 10L ?
I found out the size was all wrong.
A SB guy told me that it is more like a 13" than a 11"
Maybe it is?
My Lead screw is 7/8" and the apron measures 12 1/4" wide from end to end looking at it. The casting.
Would any of you SB 13" measure your apron width?
I would like to know any details on a 13" apron.
Mine is a R model with the oil sump , has the old single lever gear box.
Thank you , hope to hear something.
R.

I don't think the eleven shared any castings with either the 10" or 13". I've gotten photos of N and O revision aprons. N was single wall, O was double wall. I believe my lathe (an eleven as well) is an R revision. It too is double wall, but different from the O revision.

Keep a close eye on ebay, as I'm sure you're doing.

What is your serial number?

Yes you are right, I have had some input on measurements and it does not share sizes with any other apron.
Yes mine is a an R model also.
The serial is 54864
Thanks