With Red Ribbed Alox scales this model was known as model 2071r+https://leaf-vics.com/2014/11/308-sentry-alox-model-2071-r.html
I've mentioned that your knife probably didn't have own name, only some number, like mine. So, it's not Sentry neither Solo at all
As can be deduced from the attached image of a catalog page, the right model number for this knife is 1071 Ur+ (a similar knife with ribbed scales would be 2071 Ur+, namely, the difference is in the first digit of the model number).