Leak & lockup

Not much action in here, but I'll have a go at it anyway.
I have a 2004R & L69 out of a '85 MC SS - in a '88 Olds CC.
It's working ok except for a front seal leak when sitting, plus the lockup "seizes" when it gets hot.
So in the winter it's ok, but in the summer the lockup tends to stick in the state it was when it got up to temperature.
It can also have an intermediate state where it's responsive to throttling - locking up when stepping on the gas and releasing when easing up on it..
I've been thinking about getting it rebuilt to make it more durable in case I decide to do something about the engine, but it's quite expensive over here so I might as well ship it over the pond to someone who knows what he's doing. What would your approximate estimate be for a 383-safe rebuild? I don't think I'd want any shift kits as I like it the way it is, plus it's winter driven.
In the meantime, can I exchange the front seal without pulling the pump and replacing the bushing too?
Also, is the lockup solenoid the likely culprit or could there be a sticky valve (as indicated by the hydraulic diagram)?
Thanks for your time, and any answers.

The main reason for the front seal leak, is that the drainback hole is not large enough. Replacing the front pump seal most likely will not fix it. The problem where the lockup does not want to come off when it is warm/hot might be the throttle position sensor. Try http://www.drwtransmission.com/thm_200-4r.htm Tell him I sent you. It has been a long time since I talked to Don. He was pretty good at this. Dana

Thanks for the reply, tips, & referral. I'll give it a try & say hello from you.
I've read about that drainback hole and it might need attention - but the strange thing is that it can loose 4 pints just by sitting still over the winter, but when I drive it on a regular basis the garage floor keeps dry..
Also, I've ruled out any electrical issues being the cause of the lockup problem, it's entirely hydraulic in nature.

Yup, you were right, Don knows his stuff, prompt and to the point. I'd leave my tranny with him any day.
Allow me to quote his reply:
"The front seal can be replaced without pulling the pump. The bushing cannot.
The lockup solenoid is known for sticking when hot. You may only need to replace the L/U solenoid.
The cost to rebuild the unit would run $1,450.00.
If you have any further questions, please don’t hesitate. Thank you."

I'll try the seal & solenoid first then and see how it holds up. Thanks.