William;

There is absolutely nothing wrong with using a home made Drum Puller as long as it meets the two critical construction and operating requirements: Concentric compression (pulling) force application to multiple Lugstuds (3 is OK, 5 is best when maximum force is required!) with respect to Axle Stub.

While you have Drum removed, I highly recommend doing a preventative rebuild/repack with graphite grease, of the Adjusters, if this has not yet been done (only needs to be done once!).

See: https://www.sw-em.com/Brake_Drum_Notes.htm
...and: https://www.sw-em.com/brake_notes.htm

Cheers