On their most recent high-end lineup, the SVX scopes, Stellarvue claims a minimum Strehl of 0.99. Obviously, that's monochromatic not poly. As far as I know, that minimum does not apply to older scopes like your SV105T. Doesn't mean the older scopes were worse, just that you can't tell. The SV105T had imported optics figured by a sub contractor. The current SVX optics are figured in-house.
It is possible that if you contact StellarVue directly and give them your serial number, that they have an interferometer test for your telescope and could tell you your number. Honestly, though, if you are happy with the telescope I would just drop the subject. Learning whether your scope is 0.94 or 0.98 or even 0.88 isn't going to change the views any–for better or worse–and it has the potential to make you love your telescope a little bit less.