Mint Scott C13-C15 And C3 Plate Block - Should I Get A PSE Certificate

I inherited some stamps from my grandfather, who purchased them as an investment. Don't think it was one of his better investments, but now I need to figure out how best to sell these stamps. I see that PSE provides grades and certificates of authenticity, and was wondering if that would be a sensible approach given that I am not a serious collector. I see that values are going to range quite a bit depending on very specific condition, and am not sure if these stamps are high enough quality to warrant the granting.
Thanks in advance for any of your thoughts - much appreciated.

Thanks for the scans. As a buyer, I don't sell(caveat), but here is my take. At Auction I would consider getting 2 certificates.

The 2.60 has a crease either in the stamp or the gum. I wouldn't bother with that one.
The Jenny Plate block has a hinge removed on the right side. So that also wouldn't be worth getting certified.

The other two, you might consider it. Neither of those stamps are going to get even 90 grades. Maybe 80-85's but not even sure of that without detailed scans that ensure no inclusions or scuffs. A ton of these go on sale every month, yours are slightly unique in that they all have plate block numbers but most people want them all the same side. Your plate blocks aren't on the same side and one has a crease so that makes them less desirable as a set.

Still as individuals, those 2 are very collectible and will have buyers, especially if they turnout to be Mint Not Hinged(MNH) but you will pay for those certificates for about $25 each through PSE, maybe less through PSAG. But, and this might be a dealbreaker, this will take time. Figure at least 2 months, I've had some take almost 3 months because PSE was so backed up.

http://psestamp.com/servicesandfees.chtml

Someone else here can probably recommend how best to sell them via dealers/ebay to get max value.

Good Luck!

Agree with the above assessment. Too bad about the gum crease on the C15 because centering is very nice and likely would have graded 90 if not better IMO.

The plate numbers will add value to buyers no matter what. Better than not having them for sure.

Thank you so much for your responses! I had not realized the Jenny block had been hinged, but I see it now that you point it out. Granddad should not have been buying stamps!

The wait at PSE isn't a huge concern - these have been in a safety deposit box for years - but maybe with the lower values, I should just take the plunge on ebay. I have a good seller rating, but no experience in stamp sales.

Thanks again!

I agree with the assessments above, except that the C3 block is not a plate block. I believe it would properly be called a centerline block of 4.

Thank you for the clarification - centerline block of 4, it will be, and sadly a previously hinged one at that.