In answer to my own question, I’ve discovered that the stop is indeed modular. The pointer curves down under the stop and attaches there with two flathead screws. However, in finding this out I also managed to source the entire part from TB Writers Plus in Dayton, Ohio, at a very agreeable price. The happy upshot is that I will not need to fashion a pointer of my own. It looks do-able, but a DIY part would not look as good as the original, and since the price of the replacement is right, why bother?

I am not sure whether ‘plugs’ are approved on this site, but TB Writers is well worth checking out for those on the hunt for parts or machines.

I like the Touch-Master 5 as well, largely because of the late 50s/early 60s look, which is Olivetti work, I gather. One caught my eye in an antiques mall a few years back, and I thought, wouldn’t a magnificent machine like that be handy for this and that? I had been wrestling with labels in the office and was sick and tired of fiddling with printers. Home — and thence to the office — came the TM5.

There was some very minor damage, so I also bought a parts machine that appeared in a local for sale ad, but I ended up fixing both during the COVID lockdown by making some small parts from metal, so that I now have two TM5s, one pica and one elite, one being wide carriage and the other not. BUT, I am missing the ribbon covers on one, which I can’t find anywhere. I fashioned some from copper sheeting, but they just don’t look right. Any chance you would sell me them from your parts unit?

As to the platen and knobs, I do believe that all those knobs should screw off the platens so that you can swap parts as required. See the repair manual available on the inter-webs.

And as to the carriage removal: It has been a while, but I seem to recall having taken off the spring from the carriage (and secured it on the screw conveniently placed rear top left), then moved the carriage left and right to remove a couple more screws found under it on the main body. I think the tabulator on the back had to come off as well, but that ought to be removed at this stage for cleaning and lubrication anyway, so it won’t hurt to take it off. Then, as I recall, the carriage lifts or slides right off.

There is a centrifugal brake at the rear left that is part of the tabulator mechanism. It has a plastic gear (underlaid with metal) on which the plastic often seems to be cracked, and that can cause annoying problems like missing spaces. The trouble is that the gear effectively expands so that the teeth don’t mesh properly with the other gears present. Very common fault on the TM5, w

This gentleman has a Hermes 8 (one among a small collection of standards): https://typewriterdatabase.com/typewriters.php?hunter_search=2307&collection_search=My+Collection

A sentiment shared by Mac users in the 80s!

Great stuff, though I prefer fully mechanical rather than motor driven machines myself — there is less to go wrong with them, and they are certain to outlive the electrical devices.

A small point relating to servicing these pinwheel calculating machines:

As with typewriter segments, oil introduced into the pinwheels is a distinctly bad idea. Pivots, sliders, and such were, of course, meant to be greased, but the pinwheels which are the real business end of the devices are meant to be kept dry. What this means is effectively that the machines should be lubricated sparingly. Short of complete disassembly, there is no way to do this comprehensively, so servicing such machines for most of us will be a compromise with what is actually possible to do within our lights.

This site has some excellent resources should the mechanically-inclined wish to delve deeper: https://www.jaapsch.net/mechcalc/index.htm . Be warned that the operations are said sometimes to take a couple of weeks rather than hours!