I received the boiler fronts from Lionel parts (very quickly I will add).
I decided to go with the round plate, #460. I could not find any pictures of the 460 or any other Atlantic with the round plate and non-pinstriped tender. But I did find a few pictures of PRR passenger locomotives with such a combination:
And an Atlas version of a PRR Atlantic with such a combination:
Loose precedent, but it's good enough for me.
I removed the B&O face and installed the PRR face. While I had the locomotive opened I added weight to the front. This engine really finely balanced on the rear drivers and the slightest bumps or draw bar strain causes the front end to bounce up and down very easily. If I put the slightest pressure on the cab roof with my finger the front end and front drivers lift.
I made a pack of a few of these weights:
Wrapped in black masking tape and hot glued right on the back of the newly installed boiler front. Couldn't get a great pic, but here's a shot:
So here's where I am so far:
I got the microscale decals, and they look great, and include a lot of decals, including the tender pinstriping pieces. But I am not really wanting that style tender, and it would be quite a task to do all the striping. But I am impressed with the product. However I am going to try the dry transfers when they arrive.