Your concerns are valid. Parcelforce ship pretty big for that money, certainly in terms of weight anyway. Volume is pretty generous as well. I'll let you know! Thanks for the advice

No Hermes standard for 30GBP in working order that arrives undamaged will be a waste of money.  But postage is, as you know, the key to your problem.  I suggest a review of the thread "Another Machine Destroyed in the Post' - it's long, but instructive, and links to packaging advice etc.  Good luck.

Regarding the ruggedness of SG-1's : The number of these machines in my custody is equal to the number of times Kevin Durant has been the NBA scoring champion. Their Achilles heal is shifting in the carton (inadequate packing) without the carriage removed (get a seller to remove this -- fuggedaboutit) and crushing their front rail. This has happened to me twice and both were straightened and in working order.

Regarding sellers following packing instructions:  I've had mixed results, as to be expected given the variation in humans. I've had a heavy standard shipped in an over-sized carton completely immobilized by cut blocks of Styrofoam though the seller was unlikely to have made a penny, more than once, because I asked nicely. But the hardest one to take was when I had paid enough to pack properly plus a fair price for the typewriter, and I sent packing instructions which the seller thanked me for ... and then proceeded to completely ignore as it was clearly shipped in the same battered box barely larger than the typewriter that it had been stored in on a shelf!    I eventually got a full refund and still have the remains of the machine, but I would have preferred to have the machine in the original condition rather than the cash that being the reason I bought it in the first place.

Regarding the SG-3  : I saw that machine on eBay. It's a decimal tabulator and my 1926 Remington has the same.  I in fact just figured out exactly how they work. Don't accept "it's for columns of figures" as this suggests a glib answer by a person who does not completely understand how they work. The Remington was advanced for its time in having the continuous tabulator setting like the one on this SG-3 and the fact that the decimal tabulator is found on a machine this late reinforces that the function could not be replaced except by printing adding machines or computers.

If the decimal tabulator option isn't for aligning columns of figures on the right-hand side, what is it for?  All the machines I have seen (and owned) that were so equipped performed at least that function.  I have also worked with typewriters without ten key decimal tabulators (using the space bar a number of times for each figure, depending on its length) for aligning the right sides of figures.  It is essentially a speed option for those who work in banks and accounting firms, and I have seen this feature installed on machines built as late as the 1970s.  I would just imagine, mind you, that machines installed on automated typing equipment such as robotypers, would be normally equipped, since the computer interfaced with the robotyping machine would probably be set up to use the space bar the appropriate number of times to align figures on the right side.