I hope the TR will work for you. I have a friend in her mid-30s who conceived immediately after her TR earlier this year. But, like you say, age is a big factor. Hopefully, with knowledge of your cycles thru charting, you'll have a better than average chance.
If you're not doing so already, you might try taking 100mg vitamin B6 daily and see if you see an improvement in your luteal phase. Sometimes B6 is helpful in boosting progesterone and improving the LP. It can't hurt to give it a try, anyway.