Another consideration.

The last bulb I replaced was after less than an hour of operation.  I have discovered that LEDs are a much better way to do a lot less bench time replacing bulbs.  This is what I did ultimately.  Both videos are excellent instructional videos on the how to. 

Here's another video that mentions some very fine speakers as well.  The locomotive is smaller than the MP15AC.

First things first...

I buy DCC ready locos so I can install the decoder and speakers I know for their function and quality. Obviously the incandescent bulbs have to go away. There are many LED options from the smd to traditional bulb styles, 

Thanks, Nick and Duck Dogger

Thanks, Nick and Duck Dogger for your suggestions. You boys are a lot further ahead of me when it comes to electronics. I am more like find the part, remove the old one and replace it.

I am not in position to re-decoder/speaker and lights at this point. It appears a local modeler who re-guts his Athearn MP-15s may have one or more front lite boards and my thinking is to get the units back to "factory new" condition so they can be operated sparingly.  

Thanks, once again. This is why MRH is a great site.

Barry 

If you want to just replace

If you want to just replace the bulbs then I would recommend the minitronics bulbs. They are the same size and last much longer. 

https://miniatronics.com/collections/incandescent-lamps/products/micro-mini-lamp-clear-2-4mm-12v-50ma-10-pcs