Check out this page of the R&LHS website:

Out-of-Print Issues of Railroad History and R&LHS Bulletin

The publication for a long, long time was named the R&LHS Bulletin or just the Bulletin. Looking at my collection the name change occurred between issues 124 and 127.

Another place to look is the BookMine. This used to be a brick & mortar store in Sacramento, CA, but now only sells on the internet. You may have to search by the initials "R&LHS" and then page through the resulting list.

I also searched ABEbooks using author: “R&LHS” and got a long list. Then I searched within the results using “Bulletin No. ___” and got one hit for each of the issues you are looking for.

Trick is often know how to search and what alternate searches to try.

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