three NW60 SP5 BM38 SP3 servers (one per site) using VPN site-to-site
for connectivity between sites.

BM server at one site was damaged. Although it is still running we will
be removing it from service, shipping it off-site to be repaired then
returning it to service.
While the original HW is being repaired, we will be using temporary BM
server hardware to run in it's place.

Image current BM server via ZenWorks or GHOST then place that image on
new hardware. Run in interim. Once repaired server is returned, image
new (running) server to returning hardware.

Does this sound like a viable solution or is there a better way to
handle this?

We also thought about installing a NEW BM server into the TREE and
configuring it to match the current one, however using different IP
addresses and re-setting the VPN site-to-site while the current one is
up could be tricky.