1983 320i a/c repair/conversion

hi everyone,

I have a 1983 320i that I bought new back in the day.
I'm looking for some help. the a/c is not operational. I have begun the process of fixing/converting to r134a. The first two objects of my attention are the expansion valve and the receiver/dryer since they are called out to be changed in most r12 to r134a conversions that I have heard about. I thought I would replace the two items charge the system and see if the compressor comes on, check for leaks, if not go from there. There is some pressure still in the system so it has not been subject to much air or moisture that I can tell at this point.

My dilemma is where the exp. valve is and how to go about replacing it. So far I have the center console fully apart and I can see one of the capillary tubes attached to another larger tube.

So does anyone have experience with this model's a/c and is willing to give some advice/instruction?

Thanks in advance and looking forward to hearing from someone.