[Mg-t] TD Oil Seal

[Wbeech]

Friend just brought over his '52 TD and showed me the oil leaking from the
weep hole in the bell housing.  Probably a drop every 10 seconds as it sat
there idling.
 
Couldn't think of anything good to say to him but it must be the rear main
seal.  It there anything else up there that could be leaking so badly?
 
I just looked in the Moss catalog at the seal replacement kit that they
sell.  Does anyone here have any experience with it?  Are there any other
good alternatives out there?
 
Lastly, May I presume that this cannot be done with the engine in situ?  I
have never pulled a TD engine, any particular tricks?  Must I pull the
engine/tranny together?
 
Thanks to all,
Bill