I chose my subjects on
1) History
2) the chance meet with a veteran pilot, in honour i built his plane, vehicle etc
3) a striking looking subject i ve seen in museum, TV, airport, documentary, book etc
4)a built review
believe it or not it is quite often the possesion joy rather than the quality built which drives me in keeping my old models.
eg i value my hedious kid age models more even if they ooze with glue, have gaps large enough to hide an elephant, and lack painting. My most precious one is alas gone in a sad sad story.....(a chuck yager's mustang signed by him at the wing....)