I recently purchased an inexpensive 403a on eBay. New to this game I found why other bidders passed it by. Evidently it had been dropped and tension assembly shaft was bent beyond repair. I replaced the assembly with an after market $11.95 assembly. Now the problem. It ranks with my 15-91 and 201-2 so I have three go-to machines. I assume the 401 has same qualities and more than the 403.