You might even be able to drive a little wood dowel into the key way to SNUG the sleeve , and not need the epoxy.... Not a lot of LOAD on the sleeve from the steady rest jaws.... little oil goes a long way.

 Well,, I believe I like the idea of the sleeve like Steve suggests to make sure the steady rest has a no obstruction spot to run into,,,,something that long can become a dangerous wayward missle,,,if it hangs for an instant,,,??

outside the box thinking here....

slide a bearing whose ID is 1.25' onto the shaft,use electrical tape either side to hold in place,put steady rest around the OD of the bearing ??

 Years ago, the youngest son of the Refinery Mgr and crew were replacing the mechanical seal on a 150 HP vertical transfer pump out in the field. The shaft on these electric motors could be removed vertically and had been raised about 10" for clearance to replace the mechanical seal. The motor was still bolted to the pump body. After replacing the mechanical seal,,the crew chief bumped the starter to verify seal set and disaster struck!! The 2" motor shaft instantly came to speed at 3600 and centrifugal motion bent that 2"  shaft OVER and hit the worker in back of head!!

 In the following OSHA investigation, the instructor took a office type electric eraser, pulled the eraser out halfway and "bumped" the switch and showed everybody how that fatality happened in a blink of an eye.

 Be very careful with this type of possibllity!!!

It is 3 feet from the groove, a little wobble, it's just a snap ring.

How delux. Now I have a little 10" lathe, much more limited.

 i hate parting,,,,i hate parting,,,,i double dog hate parting,,,,DID i SAY i hate PARTING,,,????? 

 i KEEP THE PARTING TOOL IN A ,RAZER SHARP SHAPE,,,,USE CUTTING FLUID,,,go slow CUT EVEN SLOWER,,,,, aND MOST TIMES WIND UP USING A HACK SAW or my 4 1/2:" grinder, TO FINISH THE CUT,  i fRIGGIN hate PARTING,,,,!!!!!!

 Well,,now ole Buddy,,,you must know they invented the parting tool to use instead of them dang hacksaws,,,,,,,Did I say I HATE PARTING TOOLS,,I DO,,,,I DO,,,,!!

 I'm glad you got er done tho,,,,

There's three things that make the parting tool a challenge of geometry:

First is the cutting area and depth.  A normal lathe cut skims off a very small area... but the parting tool takes an order-of-magnitude GREATER in the cut width... and significantly more depth.  The tool's height reinforces against that cut load, but still, it's alot of pressure.

Second is reach.  The tool needs to stick out long enough to reach halfway into the part, so it's hanging out there unsupported.

Third is speed... in order to cut, the SURFACE speed needs to be properly set for a cut to work... but on a facing or parting cut, we start at the outer radius, and as we work inward, the DIAMETER of the cut surface gets smaller, so it's Surface Feet Per Minute falls off rapidly.  Those of us with variable speed just twist the knob a bit... but those with mechanical spindle speed settings, it doesn't work out that way.

Finally, kerf clearance.  The parting tool cuts through, and even the best geometry still leaves very little room for interference between the tool and stray spoils.  Easy to jam that tool, shatter it, and send pieces flying at your eyes...

The alternative to a parting tool, is the Milwaukee Porta-Band, mounted into a toolpost...  or a slitting tool on the toolpost grinder (with a significant decrease in feed ratio, of course).  Using the slitting saw, spinning slow, against the chucked workpiece, again when slitting slow, will always yield a good square end.