The Differents between Lionel 3768 and MTH 3768 Engines?

[3railguy]

The Lionel Smithsonian model is a two rail brass model that was sub-contracted out. The detail is finer and more complete than the MTH model.

[Anonymous]

Hi

Can someone tell me the Differents between Lionel Smithsonian Pennys 3768 K4 Stean Engine 18028 Verses the MTH Railking Protosound 3768 Pennsy Streamlined steam engine...both of these engines looks the same to me and i found one of the lionel 3768 engines on ebay and seen that they only mae 300 of them and it sold for 2268.00..Is the MTH one worth that much because i cant see where any of them are listed on ebay or have sold on ebay...the one that i have i would say it would be graded an 8 out of 10 because where it was only lightly ran maybe 2 hours on it...can someone tell me what this engine i have is worth? because it was just given to me from my grandpa...and i am just wondering if it is compairable to the Lionel and if someone knows how many of these engines were out?  thankyou Brandon