Problems with changing from non O/D to O/D gearbox

Some of you have already helped me to overcome some dificulties or doubts in the process of restoring my 69 MGB GT.
It´s time to call for help again from such a specialized audience.
I bought a second hand O/D gearbox, which has the reverse gear in not such a good shape (the forward gears are ok).
I have a mechanic doing the work and I asked him what about to take the reverse gears of the old non O/D gearbox to the “new” one. He didn´t agree with that solution, because the match could become unsmooth and the chances to create a steady noise (how do I say that in english? buzz?) would be high.
What should I do?
Another two questions:
First, the O/D solenoid came without the wire that should be attached to it. Is it easy to fix it? And how?
Second, should I ask the mechanic to disassemble the gearbox and the O/D to see if there is anything else needing replacement or repair (syncros, etc.)? Is it a hard and time consuming work?
Thanks,
Jose Sequeira

Jose,
You will probably get better answers than this, but I want you to know we will try and help. I don't think there is a problem with doing the reverse gear exchange the way you want. I can understand your mechanics concern, but reverse acts alone in your transmission. That is to say that no other gears share the reverse idler gear so the other gears should not be affected in any way.

If you can solder a wire onto the wire that makes the solonoid winding you'll be ok. If not, you'll have to install another solonoid.

DO NOT attempt to disassemble the overdrive unit. It is as strong as a bull and not likely to give any trouble as long as you don't mess with it.

I agree with John, don't worry about the OD unit, and reverse gear should work from one transmision to another, if it was a gear that was used all the time, it would be a problem. Jose, what color did you pick for your car?? and what are MGBs worth in Portugal? I understand that in Europe they are worth a lot of money. I hope all works out for you.

Thanks Gary and John. You have again helped me a lot. I think that nobody else answered my questions, because you gave the right answers.
You know that someone like me who have just a few notions of mechanical matters, sometimes feels lost when faces these kind of problems inherent to a classic car restoration project.
This project is, indeed, very dear to me, because after thirty years (I´m 50) I finaly bought a MGB (GT), a car that has never left my youth imaginary and which I would like to leave to my son and daughter (25 and 20 years old) so that they will keep a living memory of the sixties.
Gary, I have decided to paint it green (BRG). The engine box is already painted and the person who did it made an excelent job (expensive, also). A MGB in good shape is worth here in Portugal about 11,000 US dolars; a MGB GT 10,000. I guess this is more or less the double (or even more) of their worth in USA.
I´ll keep in touch.
Thanks again,
Jose Sequeira

Exporting MGB's to Portugal, I could retire early on that kind on money.

That,s what they bring here in the US of A. I know of a 63 roaster that brought 20k. I sold a 70 for 14K and there was a 80 model with 7k miles that brought 17k. I have just solda 78 driver for 5K.

Somebody told me that they sell for 35K Canadian in Germany, thats about 24K US. I seriously think that before long they will be worth good money in the US and Canada.