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.

All Shore scales go 0-100.  The difference is the ranges of hardness over a variety of materials and as Uwe points out it also how the tool is calibrated and force needed.  For example a Shore A durometer uses a 1.8 spring whereas a Shore D durometer uses a 10 lb spring and all three scales OO, A, D, have regions of overlap. A 90 Shore A is comparable to a 40-45 Shore D.  I suspect the Shore A was used as the A scale tool had more utility and availability than say the D scale that covered tires to hard plastics such as for pipe and hard hats.

We need to get down to facts about lube. There's some truth in not using mineral oil, but then again Tri-Flow is not always our friend.  First, it is the "RIGHT" mineral oil and the "right" weight or viscosity that has allowed many of our machines to last the 40, 60, 80 years when we find them.  Go to the old service manuals and the prescribed oil was WHITE mineral oil  and 10 Wt. viscosity.  White oil is highly refined mineral oil that is so pure it's free of the stuff that causes gumminess.  It is the oil in Sewing Machine oil (and spindle oils for those of you who know) and the proper weight that it has the duration to go service intervals and provide protection against metal to metal wear that thinner oil won't.  So no 3 in1.  Tri-Flo is a boundary lubricant in that it is made to free up mechanisms and then evaporate to leave a dry boundary film of a non sticky wax.  It's why locksmiths like it, it won't attract dust and lasts longer than dry graphite that was once used.  Where do I get this white oil?  Liquid Wrench's Light Machine Oil p/n L1004 is one easy source.  I've checked it's spec sheet and it's almost a match for sewing machine oil though a tad higher in the viscosity range but still a 10 wt. I put the oil in an applicator bottle for pin point lube that only needs a drop or two.  Cut it with mineral spirits and brush it on and blow off the excess for rust prevention without the stickiness that WD 40 is infamous for.  I do like WD40 for bright work and it really puts a shine on wrinkle finishes..  Whether you want the tried and true, or go synthetic, the main thing is will it last, will it have the viscosity for carriage trucks, spring motor bearings, and other heavy loaded typewriter parts.  The same goes for sewing machines.  It's not just that they "were built better", they had the right lube as well.