I have a Dennis Allen Mercury diesel engine available to you engine collectors.
It looks to me to be all original so in theory could be late 50’s early 60’s before Dennis got into Merco and plops very nicely without any rough spots. I haven’t run it, I don’t have any fuel, so was going to leave that to the new owner.
It is unboxed and not something I was looking to keep but a collector might want to, if you are interested drop me a text or ring me. I’ll add some photos once I have taken some.
Completed listings in eBay indicate it could be worth circa £35 so that’s my starting point
I bought it this week in a lot of Lego, Meccano, construction toys and board games.