Frank:
G'day mate. Hope you continue to enjoy the site.

IMHO, there are 2 practical options for the .375 conversion. If you are a traditionalist and want a 'pukka' chambering, it has to be the .375 NE x 2 1/2 inch.
If you want the most practical chambering, go the .375 JDJ as others have suggested.

Despite being a traditionalist at heart, I went for the latter option many years ago and have never regretted it. Here's a past thread describing my own eforts. Hope you find it useful.

Welcome to NE.com!