I am 33 - ran 4:24 in high school. Ran 3:58 for 1500 and 1:59 for 800 last spring. Foot speed doesn’t seem to have abandoned me as quickly as I thought it might. Have trained pretty consistently since college but did have about 2 years completely off from exercising from age 26 to 28. It took me well over a year to start feeling like my old self. Like others here are saying, the fact that you’re pretty close to the same weight definitely helps. It’s definitely going to be tough, but not totally out of the question. I occasionally run with a guy who ran under 4:30 for the mile in his mid 40s. Sub 4:40 is probably more likely for you than 4:20.