Saving Old Seagulls

Hi, my first post and I know nothing about Seagulls. Can anyone help with info re the engine I have been given to sell for someone plse?
From the linked pages to this site I have determined that with code GFP it is a Forty Plus Mk 2. Correct??
The number below that code though is throwing me. It is stamped quite clearly 1308BB7. The two websites I have looked at seem not to show/recognise this number. Can anyone help? I see from this site that BB7 is Feb 77-does that seem correct?
The engine appears ,like me , to have seen much better days and will not turn on the pullcord (then neither do I!), also it is quite rusty in parts. It has a brass tank,is that usual?
Can anyone suggest a value if sold in present condition ie as a non-runner?
I'm in Cornwall and note the comments re non-use of couriers should anyone be interested in this engine.
Any response appreciated,
Dagwood

john's seagull identifier had no problems with the number. It is a light weight so could go in the post but I would imagine a bit of interest in your area without having to post.
£35 to £40 as a non runner . Less as a seized engine. basic spares or repair sadly

Thanks for the guidance re price.Will try to sell local and at low cost. Not sure what I'm doing wrong with the identifier but still cannot get it to recognise No.!
Many thanks
Dagwood

I typed your serial into the identifier:

GFP1308BB7 - and it works just fine for me. 1977 Forty plus with Bing carburettor.

Thats because few have found Parcel2Go.

Google it. The last Seagull I received - I asked the vendor to use my carrier - cost me aprox £7.50.

They collect from your house and deliver to the address on the label!!