Rebuild or replace?

I love 273's. I'd build it with 2 barrel pistons and bore and hone with torque plates. Get a set of file to fit Speed Pro rings or a good set of Perfect Circle chrome rings. Have the heads checked for cracks. Mill the heads .020 and .019 on the intake side of the heads. Get a competition valve job from someone who is good. Call for a custom cam from Racer Brown, Isky, or someone that will grind a small, .450 lift and 260-268 duration, solid lifter cam. Blueprint it, I mean find true TDC, centerline the cam, measure the piston depth from the block deck front to back and side to side, measure your combustion chambers. Balance the rotating assy. Get a set of stainless steel exhaust valves, 340 valve springs or equivalent, viton seals, double roller timing chain, brass freeze plugs. I assume it is a Commando motor? Those early 273's did not need much to bring them back to new. The forged crank may just need to be polished. Resize those light rods. Add a windage tray. Do you have the Commando single exhaust? I typically recore the radiator with a 3 row core. Adjust the bands and pressure in the 904, reseal it and and replace the filter and fluid. Worry about the 7 1/4 when it goes.