Sorry for the confusion Len, but as John stated the tracks you're thinking of are those of the NS Lurgan line and are ex-Reading. The WGHSEA railroad has never had a connection with this line.

The PRR Dillsburg Branch (which 643 arrived on) started out as Dillsburg & Mechanicsburg RR., which was part of Cumberland Valley Ry. Later these lines came under the Pennsy banner. As John mentioned the D&M was electricified and carried passengers in wooden self-propelled electric traction coaches, sort of an early-day PRR M.U. car. In its heyday, Williams Grove Park was a major attraction for the surrounding area including Harrisburg. These electric cars shuttled park goers from the CV (later PRR) station at Mechanicsburg to the park, which was about half way down the D&M line. The D&M was electrified to its end at Dillsburg and the electric cars provided passenger service to that town as well as Williams Grove Park. In the early days there was a fair amount of iron ore traffic moved along the D&M line from mines along the mountain near Dillsburg. In later years minimal freight business managed to keep the PRR Dillsburg Branch intact into the Penn Central years. I forget exactly when it was abandoned and removed, but I beleive it lasted until the early to mid 1970's.

See the link for a photo of the CV / PRR wooden electric car stopped at the Dillsburg station

http://www.west2k.com/papix/dillsburgcv.jpg

John explained the WGHSEA's "lack of jacketing reasoning" a little clearer than I did, so hopefully folks can understand why the engine is the way it is. I guess since 643 has been "naked" for so long--20 years now--I've long since been used to seeing her that way and thought it was odd that people kept mentioning it!

Speaking of bare-boilered locomotives, a few other steam machinery groups with full-size steam locomotives (the Rollag, MN group with an ex-Soo Line 0-6-0 comes to mind) are running their chooches naked as well. I think at least 1 of the 2 ex-FEC 4-6-2's at FL's Gold Coast RR Museum used to run around naked and when ex-CB&Q 2-8-2 4960 worked tourist trains out of Bristol, VA she did so "in the buff".

Regards,
Jim Robinson