Do you have an NMRA gauge? If not you should.
I have about 6 to 8 of the older turnouts like yours with the metal throw bar connecting the point rails together, and they work for me.
First, check the gauge of the turnouts and repair the gauge and clearances where necessary.
Next, check the wheel gauge of all of the locomotives that will be going through those turnouts, and make sure they are in gauge. If not, repair them.
Once you have done these things, you can use the turnouts as is and no shorts should occur when running through them. I am using four axle diesels and have no problems.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
I would try them first and see if they work OK. The only "problem" is that DCC is a little more picky about momentary short circuits, so if you have a live frog in the turnout, an engine or car wheel can cause a short circuit.
http://www.wiringfordcc.com/switches.htm
I have these older shinohara turnouts and have been told they need altered to make them dcc ready. Could I get specific instructions on what has to be done. Thanks Randy