The lead rack outer dimension of RG cables

I'm trying to buy a lead rack (referred to by Digikey as a HOLDER TEST LEAD), but the rack spaces are only specified in the RG cable size.

So I found this in a handy engineering reference book:
CABLE OD (inches)
RG58 .19
RG59 .24
RG213 .41
RG214 .43

Conclusion:

The Pomona 1508 lead holder (Digikey 501-1053-ND) accepts RG58 cables, so by my calculations has slots about 3/16 of an inch wide.

I'm still looking for something smaller