Table 6

Notes:
6.3 Scott Post Dues for Cuba start with J1-J4 in 1899, overprints of US stamps. SG-D335 is the first original issue, Scott Sc-J5
6.4 Gibbons and Mackay date this as 1900, Scott as 1901.
6.5 New Zealand Officials - Mackay starts with the 1907 ½d grey (overprint of the 1900 SC84 / SG45). Gibbons and Scott go back to the 1891/92 handstamped overprints. Sc-O1 / SG-O4 is  a magenta overprint on a 1d red. Gibbons SG-O1 (SC-O6) is a violet o/p on the ½d pink (£450). I think the numbering arises from an arbitrary decision to group the overprint colours together. No matter, I'm not paying >£100 for either.
6.6 Norwegian Airmail. Mackay identifies the 1925 2 ore brown (Sc104 / SG84) issued to help finance Amundsen's attempted flight to the North Pole. Scott's C1 is the 1927 45 ore blue.
6.7Mackay date Norway's first Official as 1925, Scott as 1926.
6.9 Swedish Airmail - Sc-C1 / SG108 is an overprint of the 1910 Official 3 ore brown (Sc-O43 / SG-O20). The first real airmail is the 1930 Sc-C6, SG192 10 ore blue.
6.10 The Swedish Official SG-O1, 2 ore orange is dated 1891 by Scott
6.11 Presumably Cuba's 1935 charity stamp is not regarded as such by Scott because it is  an airmail first, thus Scott's first Cuba semi-postal is the 1939 SC-B1, SG427.
6.12 The site is developing a small leitmotif of express and special delivery stamps, see also Egypt and Russia
6.13 New Zealand#1 is clearly out of reach. I might aspire to a #2, the 2d blue at £14,000 / £550, but the best value is the 1864 1d, same design, perforated. Gibbons Simplified recommends the imperforate Sc11, SG35 at £375 / £225.
6.14 There are more South Australian Officials than there should be, including hoardes of unnumbered departmental overprints. SG-O1 is not in Scott. I am not excited by Official overprints so the will have to be cheap.
6.15 All of Bremen's stamps are fairly expensive, so rather than identify an , I would advise looking for a cheap #1.

Table 7

Notes:
7.1 The first real Uruguayan airmail is Sc-C4, SG260 6c blue of 1924.
7.2 Natal's issues #1-7 are all embossed on coloured paper, and all expensive. the is very similar to the first 'real' stamp, he Sc8 SG9 at £120 / £170.
7.3 Newfoundland's first real airmail, and a jolly good one too, is Sc-C6, SG192. The image of C1 is from Stamp Magazine, February 2006, reporting on a Cherrystone auction in November 2005 where it sold for $26,400 (est. $12,500).
7.4 Newfoundland's Post Due Sc-J1, SG-D1, the 1 cent green was issued in 1949. 
7.5 For Peru's  first stamp, Scott begins, as Mackay, in 1857 with a 1 reale blue, supplied to Peru by the Pacific Steam Navigation Co. Gibbons Simplified begins in 1858 with Peru's first home-grown stamp, the affordable Sc3, SG8. Sc1 is available on a Stamps on Stamps commemorative issue, see Other column.
7.6 For Peru's airmails, Scott and Gibbons begin in 1927 with an overprint, Mackay, unusually, starts later with Peru's first real airmail of 1934.
7.7 Continuing Peru's wealth of choice this time in the Charity section, Mackay states 1964, presumably Sc-CB6 (air post semi-postal) SG888 Red Cross Centenary. On the same page of my SG Simplified is 1 1963 Sc-CB1-CB5 SG881-885 set for  the Chavin Excavations Fund and Scott offers as B1 a 1966 issue with a surtax for tourist publicity (SG916). I'm going with 1963 to begin with, but can be persuaded.
7.8 Russia #1 (10 k blue and brown, imperf) catalogues at £4,000 and £400 (SG 2001). Russia #2, issued 1 month later (10 k blue and brown, perforated) seems to be very similar and is priced at only £32 and 25p for mint and used. I'll settle for a #2 for now - knowing my luck, and with the prices I am prepared to pay for stamps, I would probably end up with a deperforated #2 anyway. The later stamps shown are the first stamps identified in Scott for the Russian Soviet Federated Socialist Republic and the Union of Soviet Socialist Republics.
7.9 Russia airmails. Sc-C1 / SG284 is an overprint (albeit including a picture of an airplane). Sc-C2 though C5 (not in Gibbons Simplified)  are real airmails of 1923 but were never issued in that form. They were issued in 1924 with surcharges as Sc-C6 to C9 (SG417 to 420).
7.10 For the sake of completeness, I might as well include the first real Russian postage due.
7.11 I have included this as one of my favourite stamps, the first of the 1932 Special Delivery set (full set here). This is almost as good as the Egypt special delivery here - both share a delightful cartoon quality.
7.12 Mecklenburg-Schwerin #1 was issued as a group of four stamps. The prices shown are for singles (Sg1a) and a group of 4 (SG1).
7.13 Finland #1 is unaffordable, but #2 is similar and available (especially in this condition) - although the  catalogue price for the #2 is high, cut to shape, examples are available cheaply.
7.14 This Finnish ambulance belongs in my "Express cartoons" series.
7.15 For Ceylon, SG1 = Sc2 (1st April 1857) and Sc1 = SG2 (26th April 1857).  Given the relative prices, I will settle for the Sc1 as .
7.16 Ceylon Official - Scott starts in 1869 with an overprint. Gibbons SG-O1 (SG-O8) is much cheaper and so I will go with that
7.17 There is no obvious candidate for a St Helena , so look for an inexpensive example of the #1.
7.18 Scott distinguishes between the 1922 Mexico C1, which has no watermark, and the 1927 C2 which has a watermark and a deeper shade of blue. Gibbons Simplified doe not and at $60 plays 75c, neither do I.