I would really advise against high speed spooling of any tapes that haven't been played in decades. If there has been any degradation due to humidity/temperature concerns whilst being stored, You could strip the oxide off in one go. Bobert...you got lucky!
A few years ago, I had to reclaim quite an important Master tape. Luckily I had acces to a Studer tape machine that had Vari-speed spooling.
So, I set it going (very gingerly) at it's lowest speed, and kept a very close eye and ear! on the procedure...For a half hour recording (one side of an LP) It took about 2 hours in each direction, but at least the capstan/pinch roller was not engaged.
The oxide shedding was negligible, thankfully. And a successful transfer to digits then took place. Stupid boy! I just got lucky. I wouldn't dream of attempting such a process again. If a recording needs preserving. Pay an expert...Thats my advice.