"Big Red" is at the top of the list again!!!

Nope,the heater is totally different.
It is the same or very close to the '63-'68 light line though.

I was searching for something else and stumbled upon this...
http://www.ebay.com/itm/IH-INTERNATIONA ... 1e819f6f88

I checked the '66-'68 LL book against the Loadstar and the above should be the same or use-ably close. The LL had 3 heater types but 2 are so close to the LS,same core and motor...

Here's the search results for the running boards.Other than possibly thru one of the surplus sites it's iffy.
873925R11 Board,w/baffle running Left
https://www.google.com/#q=873925R11+board&start=0

873926R11 Board,w/baffle running Right
https://www.google.com/#q=873926R11+board

Also check the junk yard thread,IIRC someone listed a yard that has some Loadstars.

Here's a link to the parts book,which ckutch rod is it? See Fig. 11-013
https://app.box.com/shared/otkihx6yoa/1 ... 33907136/1

Doesn't look good for the shift boot either...
317040C1 Seal,shift lever (MV8's w/T495/496)
https://www.google.com/#q=317040C1+seal


IH used Grover air horns when your truck was built...
https://www.google.com/#q=grover+air+horns

Catalog;
http://www.groverproducts.com/catalog.pdf
The Series 1600 Dual Truktone horn is what a Loadstar would have had.They show 2 kits with that model.
I had them on my Scout,nice and loud.

The marker lights.... Haven't been made in years and only used by IH and a few fire truck mfrs. Not easy to find and probably in no better condition than yours. They pop up on epay once in a while and are usually pricey.

As for the Heater box, mine was mostly rusted as well, I cleaned it out cut a rectangular piece of scrap sheet metal and welded it place. Took most of an afternoon to make it look almost presentable but it was raining and I had nothing else to do.