They Don't Make 'em Like This Anymore

This is a Sony TC-153SD - a semi-professional portable cassette deck made in 1975-77 .  I've owned it for all of its 50 years but its time for it to go :-(  One problem is the cost of packing and delivery.  It weighs 5.4Kg (almost 12 lbs) and I'm not sure what I can pack it in to ensure safe delivery.