Nondecontructable seven-limit commas

All five-limit commas are deconstructable, and it seems that until we
get to the more complex ones, only relatively crappy commas are not
deconstructable. I get

525/512, 2430/2401, 19683/19600, 16875/16807, 10976/10935, 6144/6125,
65625/65536, 703125/702464, 420175/419904, 2401/2400, 4375/4374,
78125000/78121827

as some nondecontructable strictly seven-limit commas.