I'm sure this Radio Crap meter would serve as a basic ammeter and voltmeter and do it quite well. But, for only $10 more you can get the Sears meter I indicated that also has Duty Cycle function which is very useful for a 124 gas engine MB owner.

Additionally the Sears motor has a frequency counter, capacitance scale, temperature scale and on and on. The Sears meter is a drastically better value and in my opinion worth waiting for.

The Sears meter puts instrumentation in your hand that would've required a number of different instruments for a total of several thousand dollars a few years back. The Radio Shack meter, on the other hand, ONLY provides very basic multimeter functionality which has been available for under $100 for many, many years.

Good luck,