Taking a break from the layout for a bit, I've been working on a number of rolling stock projects. I seem to collect a lot of kits even though I already have the new layout pretty much full. I guess that's typical with Modeler though.
[attachment=40757]

Starting from the front is a Proto2000 DD boxcar, built right from the box, Beside it is a 40' Boxcar from Front Range, Left rear is a Branchline Boxcar and the right rear is a Accurail Outside braced boxcar. The branchline car was a second-hand car, missing a ladder, I replaced them all with Tichy ladders and match the paint up as best I could. I bit of weathering and they should blend in. The accurail car will be a CP car with moderate weathering, something similar to what I did with a Proto stack car a while ago.

[attachment=40758]

The DD boxcar will be wearing the CP 'script' scheme. CP had one such car as an experiment, painted in 1959 so it would be almost brand new on my layout. 

[attachment=40759]

Now the front Range car poses a bit of a challenge. Originally is was painted in Santa Fe but after I stripped it and repainted it the very fine panel lines on the car sides disappeared. I'm thinking of either drawing the panel lines in with a fine pencil or micron pen or masking and airbrushing the panel lines in with some darker brown/black. 
Suggestions?

I re-scibed the panel lines on the front range boxcar:
[attachment=40764]

I used the branchline boxcar as an example and scribed the lines to match. at first I was a bit concerned that I had scribed a bit too deep but I used a chisel x-acto blade to remove the raised lip of each scribed line and they went back to a reasonable size.
Since this is a welded car I replaced the kit's wood roofwalk with a tichy metal one and also used Tichy's Canadian ladders with the integrated stirups.

I decaled the four cars this week:
[attachment=40809]

The next step is to finish assembled and them weather them. The CPR outside braced car will be fairly heavily weathered due to it's age.  One the other hand, the CP double door will have hardly any weathering at all as the CP 'script' scheme would be brand new on my layout's era.

Looking forward to the weathering! 

I finished up the boxcars and added a gondola to the mix this week.
[attachment=40960]

After assembling, I went to weathering them all to varying degrees. Some would be almost brand new in my era (late fifties to early sixties)  and some would be decades old.
Case in point:
[attachment=40961]

This outside braced boxcar has a build date of 1927 so it would be at least 30 years old by my timeline. Time to age it 

[attachment=40962]

I started by using one of my favorite tools for this, a fiberglass eraser brush. using this I wore the paint back down to the primer and the original black plastic in some cases. It also wears down the decals. 
 [attachment=40963]
I inherited this from another modeler a few years ago. I should start looking for another as it's starting to wear out.
[attachment=40964]

After scratching the wood sides down, I airbrushed the car with grimy black, rust and dirt colors. It's got some miles on it now.

[attachment=40965]

On the other hand, the welded boxcar would be almost new so I only gave it a light weathering, mostly on the lower parts, I weathered the riveted boxcar a bit more.

[attachment=40966]

This is the gondola that I added to the lot for painting. It's another Proto unit, painted and lettered for Pacific Great Eastern in the fifties. It has a build date of 1958 so it would be quite new but on the other hand Gondolas carried a variety of goods so some stayed clean, others got dirty fast. I went middle of the road with this one. I weathered a CN gondola a while back that I weathered a bit heavier as I want to put that one into tie delivery service.

Great job and thanks for the explanation of how you did it.

Great work... The notes make it all the more interesting

Fiberglass eraser brush! I want one! Let me know if you find a current supplier, and I will also do some hunting. Just fed my granddaughter - I drew the 4 am straw!

British Model Trains (Cambridge, Ont.) has them in 2mm and 4mm sizes and also refills.

I think art supply stores may also stock them.

Found some on eBay, we’ll see how they work

I found them on Ebay, and also Micro-mark. The micro mark ones are metal brisles instead of fiberglass.