PRR N5/N5A/N5B Cabin Cars

Am I correct in assuming that N5 and N5B cabin cars were essentially the same?

Did all the N5/N5B cabin cars all have collision posts?

Were just the N5A cabin cars passenger-equipped?

In addition the Northeast Corridor off-line runs (New Haven hacks as far west as Pittsburgh or as far south as Washington; Pennsylvania cabin cars as far east as Boston), was there any other off-line/joint service/through service cabin car usage?

Geez, Louise, don't nobody know nuttin' 'bout Pennsy cabin cars? Any experts out there? Hello? Can you hear me now?

This by no means complete, but from gleaning various PRR and PC sites, as well as some PRSL publications, here goes.
All N5's were built roughly 1917-1925 with end arrangements nearly identical to N6 end arrangement.. no collision post, 4- pane end windows and vertical brakestaffs. PRSL had 3, 200-201-202 that retained this arrangement til the end of service. PRSL received 225-243 after World War 2, all with the same vintage built date, but with collison posts. One site suggests N5A were rebuilt N5's with collision posts, etc, but a set of PRR diagrams online shows these rebuilds (1937) with bars on the windows and different steps than any other N5's, suggesting passenger/express service and possible off-line service thru Penn Sta to the NH unless tunnel/3rd rail clearances prevented this . An O scale mfr says N5 rebuilds with collision posts appeared simultaneous to the N5B's, also rebuilds with AB brakes, collison posts, etc. So I'd say all N5's by the 30's had the collision posts, etc. Its hard to say when the last ORIGINAL N5 was left, but I'd guess they were gone or rebuilt by the time N5-c's and N8's were on the scene. And this was after 3 days of googling! I;d be willing to bet Morning Sun's PRR Color Guide would have tons of accurate info.....Mitch (who rode on the PRSL ones!)

Per MS PRR Color Guide Vol2 by Fischer,
..most but not all of the over 600 N5's (Blt 1914-29) were retro-fitted with the collision posts.
The N5B''s were a subsequent class of 200 cars (Blt 1941) built with the posts, higher side handrail arrangement and revised interior arrangement, the subsequent 200 N5C's (built in '42) obviously significantly different with the windows and streamlined cupolas.
Regarding Crew-Express service, in '26 45 N5's equipped with steam and signal lines and assigned to the service, later in the 60's more cars were required and additional N5's and some N5B's and N5C's transferred into the service, moving between the express and freight service as needed.

As an aside, for me these looked really cool in buried in a head-end train like the Manhattan Limited, got a Walthers model needing restoration so it'll probably get the "Assigned to Passenger Service, Railway Express Agancy" treatment accordingly.

The New Haven's version of the N5 (their NE-2 class, no collision posts plus some other minor differences) had passenger express trucks. I'm assuming the PRR's did not.