I’d get the seat tube reamed so it’s properly circular - a frame builder should be able to do that for you or an engineering shop start with a 27mm reamer then try the seatpost then only if you are still forcing it put a 27.2mm reamer down. You won’t damage the frame this way. You could also...
Oak Table in excellent condition & ideal for a hallway or side table - Height of 85cm, Length of 137cm, Width of 48cm.
Could even use this as a workbench due to the solid oak
£65 or nearest offer
Experimenting with a 68 & a 42 inner but only as a back up ring or granny ring… rear is a 10speed cassette but minus 3 cogs as got a 13-36 & shoved out for a more central chain line…