I have just finished doing my interior with a GAHH kit. I did this work myself, took two months, but I was not in a hurry (my winter project). Did it all from seats completely renewed, to door panels, kick panels, quarter panels, soft top deck, and dashboard. Best Kit on the market, and they stand by their products.
Now, as for your arm rest. Do you have the "hard map pocket" arm rest, or the soft elestic map pockets? I have the hard pockets with arm rest setting on them. The new leather comes cut and pre-sewn to fit the arm rest, and cut to fit the hard map pockets inside and out.
You have to take off the door panels, then remove the two bolts that hold the armrest/map pockets to the door panels. Then you have two screws that hold the arm rest to the panel and two screws that hold the arm rest to the map pockets.
After the bolts are free, you have to slip the map pocket bottom bracket out of the bottom holding slots (4 slots cut in the panel). Then you can detach the arm rest. Once you have the arm rest detatched from the map packet, you just peel off the old leather arm rest cover and replace with the new cover (assuming your arm rest cushions are good).
You must glue the leather to the back of arm rest and punch two holes thru the leather for the screws to attach arm rest to map pocket. You will not have to punch the back holes to attach to panel because the leather will not cover them in the back where you have glued it.
I think that you interior folks just want to do it the easy way. I would make them do it complete, not "half way". I would find another upholstery company. These cars are Benz, not Fords. Yes, it is a lot of work to install the new leathers, but it is well worth it.
Robert Hyatt
Williamsburg, VA.
1970 280SL, Red on Silver,4-speed, Euro spec; 1999 C230 Kompresser Sport, Black on Black; 1990 Miata, Black on Red, 5 Speed