Bank appraised loan and seller carrys a note for the rest? MHP with POHs

[Connor Cogdill]

Main question: The seller is asking 675k I think I could get a loan for the park for around 375k-500k(Maybe totally off just off me doing my numbers and their 8% interest rate and their typical 25% OpExp ratio and if they are all similar in running the projection of a new MH brought in $1500 per month new revenue). Can I have the seller in a second position note for the remaining 300k or less. No idea about park appraisal once I go down that route for pads and pad rent I may be getting it totally wrong on how the bank thinks and appraisals. Park Makeup 3 TOHs, 6 POHs(Ones a Doublewide if that matters), and One Empty pad that I could use for projections for DSCR according to one commercial lender.

Is there any way to better gauge what a park might appraise for if looked at for only pad rents occupied by mobile homes? -Calling agents and seeing local recent park sales? 

-Please poke holes and let me know I own one park but it was seller financed entirely.