Here goes:

Proper battery size is probably the series 49 "international" series (at sears) -- the correct battery may be the longer, lower profile than "standard" one. It will just exactly fill the battery tray, you usually have to completely remove the hold down to get it in. There is no "series 48 1/2" battery.

If the VIN is different, you have a replacement radiator support, so either extensive rust repair as been done or it's been wrecked, most likely the latter -- these things hold value well enough they don't get totalled very easily unless completely squashed. Most likely a collision with a truck, ripped radiator support, hood, fenders and grille up, missed the engine. MB should have records for both numbers, that will likely tell you original equipment and color, etc.

Windshield wash is the pedal up above your left foot -- pump slowly to spray fluid, the wipers come on when you push down. Likely doesn't work because the rubber bulb and/or check valve are long gone. The I/II is speed, defaults to low (I) when switched off.

To replace the antenna, remove the trim ring at the base and turn radio on -- I believe one knob on the radio has the three position switch behind the knob -- this will be down (bottom), mid height (center) full extension (top). Don't remember if it is on the right or left knob, though. Not marked, just a lever. With the switch set to full extension, the remains of the mast should come up out of the post with the bezel removed. You may need to grab the stump with a pair of pliers and help it along a bit.

If the motor doesn't run, you probably need a new one. If it runs and you hear the broken end flapping around, you will have to take it apart to get the plastic "tail" out.

Once removed and motor working, with radio on and motor in fully extended position, feed the "tail" of the new mast into the motor until the teeth engage in the drive gear and switch radio off. This will pull the "tail" into the motor and wind it down until the antenna seats. Guide the mast into the hollow post and re-install the bezel. May take a couple tries to get it all the way in.Teeth point forwark, I think but toward the gear in any case.

If all you get is heated air at the windshield, check the fuse for the cliamate control and the green vac line in the engine compartement -- won't run the blower with no vac. Bad fuse will give you full heat in defrost mode.

You may also have a bad climate control servo -- these are expensive, so not often fixed in older cars. If it leaks, it and the amplifer are toast.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!