Glad to hear that you got the post loosened.
The Miele from this period and level were quality bicycles, so there is no reasons yours should not be. The level of finish is primarily a measure of time and therefore money. Certainly, Marinoni built models offer other improvements, but your model is more than competent and a good value.
I thought the bicycle looked a little more orange than red in the pics. Either way, the bicycle would have gone well with the Gianella team jersey of the period. They were white with diagonal stripes of navy blue, red and orange.
I should be in Montreal, sometime over the next couple of days, so I'll keep an eye out for your bicycle.