This is only my perspective on your question.
I have only 30 hours instructing, the rest of my time is charter/aerial work/RPT stuff. Many instructors that we saw had an "attitude problem". ie they were so used to the students doing the preflights and flight plans that they had become lazy. Also, they didn't really like the idea of washing the planes and doing the maintenance too. Many instructors own handling skills get neglected because they are not actually manipulating the controls.
Now I do not know what types you have flown, so if you get offended at the next couple of sentences, I do apologise. To a chief pilot in the bush or where ever, if they see 500 hours on a C152, they are not overly impressed. It means stuff all in the charter world. Even hours in a Duchess, big deal. A C210 has only 60 hp less...One Chief pilot said to me, he basicly ignored any time on 4 seaters or less unless they went somewhere interesting, ie Birdsville etc.
One point worth noting, if you have any twin training approvals and stuff, they are useful to the charter guys...but you still need the experience to back it.
So, with regards to the charter world, think about where you are looking and at what kind of job. If you are looking at a flash twin turbine job with those hours...hmmm try again. Now, most twin jobs = 1000 hours with 500 hours on twins. The reality is usually more like 2000 hours + and at least 500 hours on twins.
This may have sounded a bit harsh and a bit disparaging to your hours but that is the reality.
------------------
reddo
Life is good 'till the next stuff up.