I found this years ago wondering how typewriter type was different from the type in a composing room of a print shop.  Fascinating to learn it starts with ribbons of low carbon steel.  Designers?  That's a whole different world, especially if a typeface is named after you. It seems some of the sources are the same for your book.  Link: https://archive.org/details/sim_print_1952-06_7_3/page/14/mode/2up?q=typewriter+type+slug&view=theater

I looked up the Vaseline Oil discussed here, and what I found is that it is a "White" oil.  White oil is a highly refined mineral oil with no olefins or paraffins that can stain, attract soil, and leave residue.  The purer white oils are used in cosmetics and some food which is probably why the Vaseline in the above links are associated with body care products.
The more industrial grades are the base for non-synthetic sewing machine oil, typewriter lubes, and precision spindle lubricants and much more.  The typewriter oils where about a 10 weight and sewing machine oil is lighter probably about a 5 weight.  I have a PDF copy of the Ames Typewriter Repair from the 1940s, and white oil was specified for lubrication except the segment which is not lubed. Any oil in question can be checked with a search for it's MSDS or SDS, and that will show the base oil be it petroleum distillates or white oil.  The only oil I found in the US that is white oil and weight is Liquid Wrench's Light Machine Oil part# L1004.  I've been using it for years and so far no sticky keys or gummy residue.
 

I have the same experience over the years with Remington standards starting with my typing classes with them in the 1960s.  A friend and recently retired typewriter repairman started his career with Remington in the 1940s and owned a sales/service business and Royal dealership close by in Eugene Oregon.  I once asked why there were not more Remingtons, it seemed there was much more Royals and Smith Corona. His reply was people felt the key action on Remington was heavier and preferred the others. Frankly I didn't think any difference was that much.

My work depended on those Rolodex. Business cards, names, phone numbers of suppliers,  contacts etc.  They were the next best thing to Yellow Pages.  It seems to me in the last decade or so the industrial environment is shifting at faster rates with new phone numbers, web addresses, etc. as companies are bought, merged or moving.  Digital is handy, but Rolodex didn't need batteries.

If you can afford it, go for it as you can learn is my criteria for accessing instruments  Next thing you know you'll be checking the difference between snow tires and regular tires etc.  I have the real deal Shore instrument from an estate clean out that was used by a sales engineer in the rubber biz so it was very affordable.  I disagree with Short's platen hardness.  90-92 is what is in the repair manuals for most typewriters such as what Ames published before it closed and what I got from them.  88 doesn't seem much of a difference but it is noticeable.  The last platen I had done by another firm used 88 and while it was way quieter there was embossing in the paper with perforation by punctuation type.  Short's main business is products for industrial , agricultural, and commercial printing.  The typewriter platens are a new side gig for them and I've come across a couple of unhappy shops.  However that they picked up the ball where Ames left off is amazing so take care and whatever is sent keep the variables and chrome ends protected.