7.5 Amp panel mount fuse to replace AGC fuse holder.

[electronics-whiz]

I was given A standard electric co. type 500b 7.5 amp 0-140V output Variac. If it's possible without a lot of alterations I would like to pull the current fuse holder and replace it with a 7.5A breaker or resettable fuse.

I looked around some, and I see the traditional square type breakers like power strips, UPS use, but this is too tall and would hit the on/off switch.
Link:https://www.amazon.com/W23-7-5-W23-X1A1G-7-50-7-5-Circuit-Breaker/dp/B00IHSY4GS/ref=sr_1_25?ie=UTF8&qid=1482797085&sr=8-25&keywords=7.5+amp+breaker

This looks better, but not sure of the brand.
https://www.amazon.com/Electrical-Equipment-7-5-Circuit-Breaker-7277-5-7-5/dp/B00IHSVDW6/ref=sr_1_23?ie=UTF8&qid=1482797085&sr=8-23&keywords=7.5+amp+breaker

Or is there some kind of a small module I could plug into the variac that has a breaker in it?
I assume because the fuse is on the output side I should go with a 240 rated breaker although not sure if 140V would do much to a 120V breaker.
Looking at the datasheet on the second one it looks like it is the best choice if it is any good, not sure the specs are metric or english in the datasheet though.

The current fuse holder is 1 3/4 inch from the mount flange to the back with 90 degree terminal at end. Looks to be about 1/2 inch diameter Takes a 1 1/4 long) by 1/4 (dia) AGC type tube fuse.

I was going to get some fuses for it, but if using a breaker is an option then that's even better. I'd prefer something with some delay so I can start motors, etc on this without it tripping. Not sure if thermal or magnetic breaker would be better for this application.