Following different lines of reasoning (most likely all faulty) - I can convince myself that the current estimate(s) of the Hubble age may be off by a factor or 2 (more or less) depending upon the physiology asssumed for space and the model used to describe the expansion rate - specifically: If the cosmological redshift (CR) is attributed to stretching space (per Harrison's description as incorporated in Wiki) then the scale factor "now" divided by the scale factor "then" seems consistent with the present estimates 70+ and an estimated age of about 13.5 billion years. This description, however, implies a substantive property of space akin to what one might attribute to a medium - no one seems to have a convincing argument of why space can stretch so as to lengthen the wavelength if the void does not have medium-like properties. On the other hand, if the CR is in reality a Doppler affect as originally thought (prior to Robertson's interpretation) - and as sometimes argued by some members of this Forum, then z is not representative of the present size of the Hubble Scale because the red shifted light has taken about 13 billion years to arrive from the most distant sources - during that 13 billion year travel time since the photon was launched, the universe continued to expand - perhaps doubling in size to 26 billion light years - or more if q is negative. A third way of viewing the CR which does not require a stretching medium embraces the notion that the receding nebula are not moving wrt space as is the case with kinematical motion that relies upon mediums (such as sound in air) - but rather, the light sources are comoving with respect to local space, that is, the spatial coordinate system is expanding - In this model, light sources are wafted along by the local space - this would seem to explain the faster than c recessional velocity consistent with redshift data But like the kinematical model, the data would "out dated" by the time it is received - the distant source and earth having moved further apart (with their own local space) during the photon's travel time - the snapshot taken by the captured redshift data from the most distant galaxies would seem to be correct only in the stretching space scenareo - but not in the comoving space model. As in the kinematical formalism, The difference would seem to be further augmented if the universe is accelerating. While the velocity distance law is well established - Does it really make sense to define the present age of the universe based thereon?