How do I identify a Lionel part number, and where can I buy it?

The caboose is only a snap-together shell and a few detail parts, so an exploded view is probably not needed. The bobber caboose chimney is 9067-50 "Stove Pipe". Lionel has it, and most other parts sources too.  A parts list is available at 7-4 of the Lionel Parts Lists available on the Lionel website. The vast majority of Lionel production from 1970-2004 (or so) is available there.

A plurality of extant parts lists and diagrams from 1900-1941(Prewar) and 1945-1969 (Postwar) have been published in a few books and were once available as a CD from Olsen's Model Trains

The Kline engine is based on the MARX 333 and (I think) was produced in the 1990s. Since it is conventional, any convenient, correctly sized electronic reverse board should be easily swappable into it. You can also just wire in a bridge rectifier for forward-only operation. You should probably contact Brasseur, the only practical Kline parts source.

UPDATED 11/16/2022: Dead links removed, others updated

First of all, thanks for all of that helpful information.

I went to order that "Stove Pipe" for $2.15.  However I couldn't go through the checkout process, when I saw Lionel was charging $10.00 for Priority Mail shipping.  I'm sure Lionel uses genuine plastic, but I can't imagine their packing materials are worth that much.

Does anyone know a supplier that doesn't use shipping charges to profit enormously?

Lionel charges a standard $10 for shipping parts if you get a tiny washer or 10 pounds of parts.  Keep in mind it will most likely come in the Post Office Express Mail small box that costs $7.50 to ship, so your paying Lionel $2.50 to pay for packaging foam, order printout, plastic bag the part comes in, some shipping tape and LABOR.  $2.50 isn't unreasonable in my opinion.  

I get Lionel parts a couple times a month in to do repairs for the LHS, it is painful to place a order for a low dollar amount such as the $2.15.  Think of some other items you may need such as lights, traction tires, etc.  You'd be surprised the number of other items you come up with that comes in handy.

Jim

Check with Forum sponsor S & W parts, he is showing it in parts list.

I let my order build up in my cart at Lionel until it reaches a couple hundred, then the $10 isn't so painful.

I have some in stock, what color?

@Chuck Sartor posted:

I have some in stock, what color?

Black.

@Jim Sandman posted:

Lionel charges a standard $10 for shipping parts if you get a tiny washer or 10 pounds of parts.

Jim

If only the technology existed for small items to be shipped in small containers at a lower charge.

There is, called a padded envelope. Drop me a line.

I end up shipping tons of padded envelopes for small parts, typically the postal charge is in the $3-4 range.  Add the cost of the padded envelopes and it's still well under $5 actual shipping cost.  Truthfully, I don't find the Lionel shipping charge unreasonable, and MTH charges more for small orders.