Joe Yau has the right perspective here, pants of the Golden era seemed 'large', like Fluorscheim Brogue wing tip shoes.
(Imagine a gentleman in the '30s, sharp full-bodied double breasted suit, teetering in tiny loafers with tassels...)
Sig has 'kit type' vacuformed pants in their catalog: Pricey, but available. (hit 'info' for pics)
I got some vacu-formed pants for my Gee Bee in 1976, (Sheldon's hobby shop in San Jose) they stocked a range of sizes from 3" to 12".
But I ended up cutting and laminating my own out of balsa sheet...(as in the Sterling Mr. Mulligan kit)
And like stated above, you can design your own size and shape. Easier than you think.