Table 4

Notes:
4.1 Gibbons dates Modena SG1 (Sc1) as 2nd Sepember 1852 and SG3 (Sc2) as 2nd June 1852. There is no Gibbons #2. (Gibbons Part 8, 5th edn).
4.2 Netherlands Airmail. Mackay starts in 1928. Scott (and Gibbons) show SC-1 as a 1921 10c red 'used to pay airmail fee charged by the carries, KLM'. The 1928 issue is C4 / SG242, 5c green at £9.25 / 15p.
4.3 For Oldenburg, Scott's Sc1 is the 1852 1/30th thaler black on blue, SG2 (£300 / £20). Gibbon's first - SG1, 1/3 grote black on green (£1,000 / £1,000) is Sc4 and dated, by Scott as 1855.
4.4 Reunion Airmail. C1 / SG174 (£200 / £150) is an overprint of Sc141 / SG149 50c red (25p / 20p), commemorating the flight of the Roland Garros from Reunion to France by aviators Laurent, Lenier and Touge in Jan-Feb 1937. The first 'real' airmail is the 1938 C2 / SG181 3fr65 blue and red at 60p / 85p - that's the one for me.
4.5 Roman States. Gibbons numbers the paper variants of the ½ bajocchi black on grey and lilac separately as SG1 through SG6; Scott lists six more precise paper colours as 1 though 1e. No dates are given beyond the year and the prices range from £32 to £1,300. The cheapest mint is black on dull lilac, SG5, Sc1 at £12.
4.6 Thurn and Taxis is divided in both Scott and Gibbons into  the Northern and Southern Districts. Both catalogues number sequentially.
4.7 A Brunswick #1 is clearly out of my league, however the same single design was used for 5 years and remained in issue for 11. I have settled for an SC5, SG5, the 1856 ¹/₃rd silbergroschen black.
4.8 Luxembourg Sc1, the 50c green, was issued in 1933, so Sc2, the 75c brown is the first airmail.

Table 5

Notes:
5.1  Sc62 / SG69 is the only Cape of Good Hope stamp issued in 1900, so presumably this is the one Mackay refers to. There were Mafeking Besieged overprints in the same year (Sc162-166) - it is possible that these are they.
5.2 I posed the question in FICC which is the last stamp. The last CoGH set was a series of definitives in 1902-04. Two of these were issued in 1904, the 2d brown (Sc65 / SG72 - £4.50 / 50p) and 21/2 d blue (Sc66 / SG73 - £2.50 / £5.50) With the first issue the criteria are date and then lowest Scott number: for the last it is going to be (latest) date and the highest Scott number - usually the highest value in a series. If there is extreme variation then I will go for the cheapest in the set.
5.3 Scott dates Chile #1 as 1852, Gibbons as 1853.
5.4 The first Chile airmail is an overprint on an otherwise unissued stamp. The first "real airmail" is the 1931 Sc-C22, SG144, 5c green.
5.5 Scott's first Chile Post Due and Official are both handstamps.
5.6 Given the price difference between the Portugal #1 (£3,000 / £850) and #2 (£800 / £16), I have sensibly settled for the latter. There is also a Stamps on Stamps 150^th commemorative issue here.
5.7 Philippines airmail Sc-C1 is an overprint, as are the many airmail issues until 1941 and Sc-C59, SG335.
5.8 The Philippines 1942 Charity was issued under Japanese Occupation - see page 25.
5.9 Clearly the collection must include a Tasmania inscribed Van Diemensland, in which case the FSP will be the 1857 1d carmine. [The example above was sold as an 1865 SG28 1d dull vermilion and priced at £1- close enough.] The first stamp inscribed Tasmania is the 1858 6d lilac: the FSP here is the 1864 version.
5.10 Although not strictly a commemorative, the 1899 Tasmanian pictorial series is pretty enough to include the first of the series.