Thanks for the suggestion. However, I did a search on that site prior to posting here and sent an email to Mr. Petrov who has not yet responded.
The scant information I have gleaned from the internet thus far is that Dubeil worked for Hoffman Arms in Oklahoma until its closing, and then moved to Sherman, Texas. One of the posts suggests that the first "Dubeil" rifles were made on actions obtained from Ranger Arms when it closed, rather than the later patented Dubeil action.
I have not yet had the opportunity to inspect the rifle which has been offered to me. As soon as I can arrange that, I will try to take some photos and post them.
When Dubeil Arms folded, apparently the remaining rifles were donated to the Cody Museum.
Again, any additional information would be much appreciated. If anyone would like to venture an opinion as to range of value for a rifle which is reputedly in excellent condition and capable of shooting very small groups, I would welcome those opinions as well.