While it would be best to start small and work up However, if this isn't an option with the available toys I think you can certainly give it a try. I reckon that the ability to accept a certain size of toy is more a matter of training your mind and anus to relax enough rather than a major physiological stretching. Given that it's a matter of you inserting a toy yourself I think you are much less likely to do yourself an injury than you would be if, after a long lay-off, someone else was driving the toy.
So, as long as it's a toy you have accommodated before and you go slowly on the insertion with lots of lube and stop if it starts to hurt you should be OK.