McGyver would be proud!!
The radiator was boiling over and oil was dripping from the bottom of the car (adding to the automatic rustproofing feature of the Spitfire!). I looked all over the engine to find the source of the leak to no avail. After the radiator cooled down (electric fans are nice) I restarted the engine and discovered the oil pressure switch pumping oil out like it was free! Problem #1 was solved. Now I had to repair it without getting AAA involved. I had a trunk full of tools, but no spare parts.
After getting the pressure switch out, I rummaged through my trunk, toolbox and even looked at the side of the road for ideas. I was convinced that even the famous Swiss Army Knife woud not come into play in a primary role this time.
I finally remembered that basically, any car is a collection of spare parts, assembled in such such a manner so as to drive in close formation. I set about removing bolts from any assembly having more than one holding it on. After going all around the car and discovering that most are too small, I came upon the starter motor. Yes, this is virtually the next door neighbor to the pressure switch.
Removing the top bolt, I discovered it to be a perfect fit. Threading the nut onto the bolt first, I then threaded the bolt about 1/2" into the pressure switch hole. I used the nut to tighten down against the block and lock it in place.
After putting the obligatory 2 quarts of oil that we all carry in the trunk in the engine (this is on our "minimum equipment list"), and replacing the coolant collected in the overflow bottle and a liter of spring water from the cooler, I was able to drive home without further incident.
I realize this is probably pretty basic stuff for you veteran mechanics, but for those of us that have been prevented from working on our own cars since computers found their way under the hood, it was a good feeling. Hopefully someone else will be able to benefit from my experience.