Manny, just for some further information. The two Bangs are not made by different manufacturers. They were all made at the Chinese facility called Sanda Kan. The O-Line Reproductions (OLR) was a repackaging of RMT products that they did not apparently have the cash flow to pay for. Heartland Hobby, a train distributor, had the products repackaged in a variation of the defunct K-Line packaging, took delivery and distributed the products to retailers. So, the OLR stuff was more recent than your other BEEP. In fact it was the last of Sanda Kan produced RMT products. The newer RMT products are most likely being made at the same facility that produces trains for Menards.
Aside from the different packaging, one way of telling the OLR marketed BEEPS from previous versions are the painted handrails. To my knowledge, RMT boxed models always had silver handrails. Maybe there was an exception or two, but every BEEP I've ever seen has had silver handrails. The last bunch of OLR marketed versions (PRR, Long Island, Cancer Cure) had painted handrails.
Now I do remember RMT making some changes to the circuit boards of the BEEF F unit style diesel to make them run faster. The BEEP and BEEF shared the same chassis, save for maybe some minor mounting changes. So just theorizing here, but sounds to me like that last run of BEEPS could have had the same circuit boards that were in the BEEF.
At any rate, you want to find either another OLR version of the BEEP or another earlier made version of the BEEP that had a tether cord. And actually I don't remember when RMT started adding a tether cord to the BEEP. Probably another change made with the advent of the BEEF. I know my BEEP didn't have one but mine was a very early made version.
