Hello Scott,
Yes the sender pulls straight out. Caution!! This sender is attached to the guage via a tiny capilary tube. If it is cracked or cut the gas will leak out and the guage will no longer fuction.
Often the sender will become rusted in the fitting and after removing the retainer the bulb sill will not pull straight out. try soaking with some solvent first. Remember too much movement in one place will fatigue and break the capilary tube.
The last resort alternative is to leave the bulb in the fitting by carefully unwinding the fitting from the head with the bulb in it. Allow the twist in the capillary line to be distributed along the whole line and not just in one spot.
Fortunately these expensive guages can be repaired by some automotive instrument specialists. You will need to send the entire guage with bulb and capilary tube off for repair.
Running without a working temperature guage is extremely risky. It could be the most expensive mistake you ever make! A temporary hook up can keep you safe until you restore your original.
Yes I have made an off the shelf guage work temporatrily. You will need to find a bulb which fits and a metric retaining nut. If you can find another original retaining nut from a bad guage or a sedan parts engine, simply cut a slot in it so it can be fitted over the tube of the off-the-shelf guage and install! The off-the-shelf guage can be temporarily hung below the dash until your original guage is repaired. Try Walmart for an inexpensive capilary style temperature guage.
I will try to post some photos later.
Additional note, nearly all Mercedes cars used the same bulb sender, fittings and capilary type guage up until about 1973, (later guages had electic senders). You can remove a working guage from almost any common sedan before 1973 and use it temporarily by hanging the guage below the dash.
If the repair time is not too long it may be easier and safer to just send the original out for repair and avoid driving the car.
Joe Alexander
Blacklick, Ohio