Colt Official Police Maine State Police Gun

I have acquired a Colt Official Police with 6 inch barrel, serial # 5511XX with an "L" underneath. On the backstrap is engraved "Me. S.P. No. 30." I have confirmed verbally with the Maine State Police that the first guns issued to the newly formed ME state police in the mid 20's were Colt Offical Police with the engraving and that there is a similar one on display at SP headquarters. The wear on the gun is also consistent with a duty gun that saw 20-30 years of service. There is a lot of white on the barrel and cylinder and the right wood grip is worn smooth in places. Function and bore are excellent. I have several questions regarding this gun and would very much appreiciate some help.

Can anyone tell me the approx. manufacturing date from the serial #?

Does the gun have more value to a collector because of the engraving and the connection to the ME SP?

Does the wear hurt the value of the gun in this case?

What is the approx. value of the gun to a collector?

thanks in advance..... Steve in Maine