No worries Espee, these were the easiest converts, no milling required. I was surprised.

I did sand the speaker baffle a tad also. Those we Cruse Engineering sugar cubes 13 x 18 x 5mm ... I sanded them down to like 3 mm thick.

Fun fun fun, I get a thrill making them Railpro savvy. - Good times.

LVRR1856 I understand your dilemma with so many locomotives. I too started collecting my locomotives over 40 years ago and have a number of Athearn and Yellow box Atlas. Fortunately most of my recent acquisitions were Broadway Limited and they are very suited for digital and Railpro. I have converted pretty much all of them or while be doing the last batch of Broadway Limited soon. I have decided to not convert my Athearn as it would also require re-motoring them which I don't want to do. I have avoided the AHM/Riverossi locomotives like the plague as they are very old school technology. I do intend to convert my Atlas Yellow box locomotives are they are very good runners, however some will require some creative methods to fit the modules in. I have 3 S-1 switchers next on my list and the modules are slightly wider than the cowling so I may need to bring out the dremel tool. All that said, I want my best runners and best detailed locomotives on my layout. The Athearn are not bad but the detail is not as good as more modern models so I have eliminated converting those. Bachmann is another locomotive that I will not be able to convert. The design of Bachmann is unusual and while I have a number of K-4's I ripped out the motors and will just use them as static scrap models awaiting the torch in the yard. These decisions have to me made considering practicality, economics and physical limits. Older locomotives just did not imagine adding anything additional and used up all the space with weight, etc. You have to take all these factors in to determine what will get converted and what will not. It may seem overwhelming to calculate your total fleet and automatically think that they all have to be converted. Once you make these decisions it will seem like a loss at first but in the end you will have to compromise and you will have your best locomotives running with Railpro. Whether you sell the rest of just shelve them is up to you but you start to accept your decisions and feel better about them.

I Just ordered some LM3s from SSS and got the same response of lack of enthusiasm for Railpro but I think we can change that. I had been waiting to order from the few dealers but they all seem to be out of stock. At SSS I could not order from the website since they were out of stock so I sent an e-mail stating my needs and they will be ordered for me. I can understand not wanting to tie up a large amount of money in stock that doesn't move. Although it may take a month or more to get them back in I have been waiting since the end of the year and had to take a proactive move to get the LM3s. I suspect that it may be that there are issues with tariffs and supplies coming out of the east. I let SSS also know that will be wanted to order a few more at the end of the year so hopefully they will see more demand and keep them in stock once they are more available. I really loved working with Bill at PDC and that was a huge loss but that is the way it is. I hope SSS will become my main go to like Bill was.

Sorry about that - couldn't see that there were attachments when using my "smart" phone. 
Nice work there - thanks!

Hi Espeelark,
There is a few pics there in my first post ... can you see them ?

Anyway here is my second GP-30 - P2k, even easier - no Sound, I used a LM3, a Digitrax 1" - 8 to 9 pin harness, and 2 LED bulbs with built in resistors. No cutting or soldering. Light filing the screw hole nib for old circuit board.

Just wired the LEDs into the P2K 8 pin top part of the plug with the little push on caps. I timed myself on the lights - about 7 minutes, strip wires,
twist, and cap ... they work great.

Ran it with the other unit - consist works great.

Rolling right along - just bought a pair of NOS - P2K GP30's. They were still new in box, never opened.
Of course to be expected on both engines - all 4 wheel gears were cracked. I can change these out in minutes now.
I buy packs of either red or black gears - reuse the old wheels. The Walthers sets are like $7.50/pair ($15/loco).
Just using new gears, can do for about $4/loco.

I pull off the old resistor board, popped in a new set of LEDs with built in resistors, rewired into the 8 pin plug, just a minor file down of the nibs
on the weight where te screws were for the board. LMS-3S set in there nicely along with 9 to 8 harness on one end. (used 1" version).

13mm x 18mm x 3 mm speaker and box from Crude - engineering, fit onto of rear light notch.

No cutting required.

I did run into a short problem. There was a tiny bit of corrosion on top of the 8 pin plug, after several other attemps to fix, finally found it.
scratched it up and cleaned with Isoprop Alcohol ... fixed it. Must have been a reaction from old flux ... good now.

Runs great. Number 2 will get just a LM3 no sound ...