1. The tech should NOT have charged this system when he knew the location of the leak and did not fix it. Evidently this was a general repair shop, not an auto a/c repair shop. All the a/c repair shops can replace the hose using your original fittings and do it relatively inexpensively.
2. You are in Texas, don't even think about changing to 134, just find someone who is a real a/c guy with a/c equipment. This should not be a big deal, just find a shop that will recover your R12, rebuild the hose, evacuate and charge.
I wish you were nearer to me. I am North of Paris and in the thinking process of gearing up to open an auto a/c and electric shop.
If you go to Dallas ever, there is a very good, honest and reasonable price shop called McCain's on Floyd Circle near the main TI plant in Richardson.