Guess what – I had an 'answer' in my library all along! I know, put it down to a CRAFT moment (just notched up my 70th) ;-)
It was in Tradition magazine #67, published in the 60s, in a short piece by P J Haythornthwaite, Uniforms of the Swedish Army & Navy 1814. Pommerska Legion is shown in rear view in what appears to be a very French style uniform: black shako with brass badges & chin scale, dark green pompom and plume, light green cords, yellow cockade with white centre; jacket dark green throughout, with yellow piping (on collar top and bottom, shoulder straps, round cuff tops, double turn-back edges)and two bars of yellow lace on the collar, brass buttons; dark green overall-trousers with yellow 9side seam0 stripes; black leather belts. black cartridge box with brass (hunting horn) badge; brass hilted sidearm ('sword bayonet' style with open grip) in black scabbard with brass tip. (My additions to original text in brackets).
Another earlier article, similar title, by Witney B Young MD (sic!) includes the following description: The Pommerska Legion: probably raised in Pommerania wearing a 'Kiwer' with yellow metal fittings and green cords. Cockade above a white emblem with a coloured centre, green plume and yellow pompom. The coat was green, double-breasted, with yellow metal buttons. Collar, cuffs, shoulder straps, and turnbacks were green piped yellow, and there were two bars of lace on the collar. Green pantaloons (sic – overall-trousers) with yellow stripes at the side.'
What I also didn't know was that there was a 'Pommerska Landwehr' too! They are descibed in Young's article as wearing 'Kusket (the Swedish 'top hat') with black oblique chenilles (comb) and a yellow hat band, white plume, and cockade. Dark blue coat, the same length all round the skirts,no turnbacks, single breasted with yellow metal buttons down the front, yellow collar and cuffs, yellow piping round dark blue shoulder straps. Grey pantaloons. The coat possibly was similar to the Prussian 'Litewka'.'
This unit also appears in the Haythornthwaite piece as 'Probably Pommerska Landwehr'. Black hat with black crest and plume, red cockade with yellow centre, yellow band round hat, yellow cockade-loop with brass button; dark blue coat with yellow collar, cuffs and lapels, brass buttons, blue shoulder-straps edged yellow; grey breeches, black gaiters; white belt (over left shoulder only).
FWIW the Young piece answered many other unknowns for me – it covers the infantry and artillery in some depth but not the cavalry. Well worth getting hold of if you are contemplating doing any Swedes I'd say.